in  tfje  Cttp  of  J^eto  Iforfc 
College  of  ^fjpsictans  anb  burgeon* 


Reference  Hibrarp 


A  STUDY 

IN    THE 

Epidemiology  of  Tuberculosis 

With  Especial  Reference  to 

TUBERCULOSIS  OF  THE  TROPICS 
AND  OF  THE  NEGRO  RACE 

BY 

GEORGE  E.  BUSHNELL,  Ph.D.,  M.D., 

Colonel,  United  States  Army  (Medical  Corps)  retired.     Honorary  Vice- 
President  and  Director  National  Tuberculosis  Association  of  the  United  States. 
Member  American  Climatological  and  Clinical  Association. 


NEW    YORK 

WILLIAM  WOOD  AND   COMPANY 

MDCCCCXX 


1*0- 


COPYRIGHT,    1920 

By    WILLIAM    WOOD   &    COMPANY 


Printed  by 

Hamilton  Printing  Company 

Albany,  N.  Y. 


PREFACE 


To  understand  tuberculosis  of  the  temperate  zone  and  of 
our  race  it  is  necessary  to  know  something  of  tuberculosis 
as  it  affects  other  races  which  live  under  different  social, 
economic  and  climatic  conditions.  No  apology  is  therefore 
needed,  it  is  hoped,  for  this  little  book,  although  the  views 
as  to  tuberculosis  set  forth  in  it  are  not  supported  by  any 
original  investigations  of  the  author.  The  aim  has  been, 
rather,  to  collect  and  discuss  facts  and  in  so  doing  to  make 
known  to  the  English-speaking  public  some  of  the  very  im- 
portant but  little  known  epidemiological  data  which  have 
been  published  in  widely  scattered  and  often  more  or  less 
inaccessible  periodicals  and,  the  greater  part  of  them,  in 
foreign  tongues.  With  this  end  in  view  the  writer  has  not 
scrupled  to  make  copious  extracts  of  papers  on  the  epidemi- 
ology of  tuberculosis,  mostly  from  the  German,  for  the 
translation  of  which  he  assumes  the  responsibility. 

The  work  in  its  first  draft  was  an  essay  on  tuberculosis 
of  the  tropics  and  of  the  negro  race.  It  has  outgrown  its 
original  framework,  but  it  has  been  thought  best  to  retain 
the  references  to  the  tropics,  especially  those  which  have  a 
practical  bearing  upon  prophylaxis,  treatment  and  the  like. 
While  the  principal  object  of  the  writer  has  been  to  further 
the  acceptance  of  certain  views  of  universal  applicability  in 
phthisiology,  he  has  also  borne  in  mind  the  need  which 
exists  of  a  greater  clarity  of  the  conception  of  tuberculosis 
as  a  practical  problem  affecting  races  as  yet  not  fully  tuber- 
culized  and  hopes  that  what  he  has  written  may  serve,  not 


IV  PREFACE 

so  much  as  a  formal  treatise  on  tuberculosis,  but  rather  as 
a  study  which  by  emphasizing  certain  important  but  too 
much  neglected  distinctions  may  stimulate  inquiry  and  may 
also  prove  of  some  practical  benefit  to  the  physicians  who 
encounter  the  disease  in  remote  regions.  The  tuberculosis 
of  the  civilized  negro  has  been  discussed  in  some  detail,  not 
simply  because  of  its  interest  as  an  epidemiological  study, 
but  also  on  account  of  its  practical  importance  to  the  citi- 
zens of  the  United  States. 

Great  difficulty  has  been  experienced  in  determining 
what  the  truth  is  as  to  the  prevalence  and  severity  of  tuber- 
culosis in  various  parts  of  the  world.  With  regard  to  some 
countries  it  has  proved  impossible  to  form  any  conception 
as  to  what  the  actual  facts  are.  No  attempt  has  therefore 
been  made  to  report  upon  all  tropical  countries  —  there  is 
little  use  in  repeating  statements  that  tuberculosis 
"  rages  "  here  or  there,  if  no  further  information  is  fur- 
nished. It  is  the  way  of  the  epidemiologist  to  write  pessi- 
mistically on  tuberculosis,  as  if  something  could  be  gained 
by  creating  alarm.  But  this  is  not  the  standpoint  of  the 
writer.  If  tuberculosis  is  really  ravaging  the  world  and 
if  nothing  can  be  done  to  restrain  it  as  a  world-plague,  the 
proper  course  is  to  dismiss  the  unpleasant  subject  from 
one's  mind  as  completely  as  possible.  On  the  other  hand, 
if  there  is  a  prospect  of  improvement  rather  than  of  dete- 
rioration —  and  the  experience  of  the  last  half-century 
should  encourage  us  to  believe  that  this  is  the  case  —  every 
one  interested  in  the  prevention  of  the  disease  should  be 
anxious  to  lend  a  hand  wherever  possible. 

The  suggestions  as  to  a  practical  program  in  the  epi- 
demiological study  of  our  own  communities,  as  well  as  those 
of  other  peoples,  are  submitted  with  much  diffidence  with  a 
view  to  stimulate  thought  and  investigation. 


PREFACE  V 

The  role  of  the  von  Pirquet  test  in  the  epidemiology  of 
tuberculosis  is  destined,  it  is  believed,  to  become  of  increas- 
ing importance.  Especial  attention  has  therefore  been 
paid  to  it  in  the  hope  that  the  Anglo-Saxon  may  be  inspired 
by  the  example  of  the  French  and  of  the  Germans  to  make 
use  of  it  on  a  large  scale  —  not  only  in  the  tropics,  but 
also  at  home. 


Digitized  by  the  Internet  Archive 

in  2010  with  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/studyinepidemiolOObush 


CONTENTS 


Chapter  I 
The  Pre-Kochian  Era 

Chapter  II 
The  Modern  Era 

Chapter  III 
Tuberculized  Races 

Chapter  IV 
Non-tuberculized  Races 

Chapter  V 
Modes  of  Infection 

Chapter  VI 
Pathology  and  Pathological  Anatomy 

Chapter  VII 
Diagnosis,  especially  Tuberculin  Diagnosis 

Chapter  VIII 
Prophylaxis  of  the  Non-immunized 

Chapter  IX 
Treatment  of  Tuberculosis  in  the  Tropics 

Chapter  X 

Tuberculosis  of  the  American  Negro  and  of  the  American 

Indian 

Chapter  XI 

Epidemics  of  Tuberculosis 

Chapter  XII 
Some  Practical  Considerations 

Chapter  XIII 
Summary  and  Conclusions 


Epidemiology  of  Tuberculosis 


CHAPTER  I 
THE  PRE-KOCHIAN  ERA 

It  is  difficult  for  us  who  have  so  long  known  that  tuber- 
culosis is  a  transmissible  disease  to  place  ourselves  in  the 
position  of  the  practitioners  of  previous  generations  who 
for  the  most  part  believed  it  to  be  non-infectious.  It  is 
true  that  in  countries  like  Italy  where  the  disease  was  com- 
paratively rare,  it  was  believed  to  be  highly  infectious,  but 
this  belief  originated  there  rather  in  the  fear  of  an  un- 
familiar malady  than  in  any  definite  pathological  concep- 
tion. Early  medical  writers  differed  greatly  among  them- 
selves as  to  this  point,  but  on  the  whole  the  verdict  was 
against  the  infectiousness  of  the  disease.  Laennec1  speaks 
of  the  contagiousness  of  tuberculosis  as  very  doubtful  and 
cites  the  familiar  facts  as  to  the  absence  of  infection  among 
those  who  nurse  the  tuberculous  but  goes  on  to  say  that 
many  facts  also  show  that  a  disease  which  is  usually  not 
contagious  may  become  so  under  certain  circumstances. 
Even  Villemin's  experiments  which  to  our  minds  definitely 
prove  the  infective  properties  of  tuberculous  sputum  and 
tissues  were  not  frankly  accepted  in  such  a  way  as  to  influ- 
ence medical  practice.  For  example.  Flint  states  as  late  as 
1873 :  "  The  doctrine  of  the  contagiousness  of  the  disease 
(tuberculosis)  has  now  as  hitherto  its  advocates  but  the 
general  belief  of  the  profession  is  in  its  non-communicabil- 
ity."2     As  von  Behring  says  the  decisive  victory  of  Ville- 

1  Cited  by  Von  Behring,  Beitr.  z.  Experimentellen  Therap.    Heft  11,  p.  20 
3  Austin  "Flint,  Practice  of  Medicine,  1873. 


2  EPIDEMIOLOGY  OF  TUBERCULOSIS 

min's  doctrine  was  gained  only  after  the  discovery  of  the 
tubercle  bacillus.1  The  problem  then  was  to  account  for  a 
disease  —  consumption  —  which  was  not  due  to  infection 
and  which  had  its  seat  in  the  lungs.  What  more  natural 
under  the  circumstances  than  to  class  it  with  other  respira- 
tory diseases,  bronchitis,  laryngitis,  pneumonia.  These 
diseases  according  to  the  prevailing  view  were  non-infec- 
tious and  were  caused  by  exposure  to  the  weather,  and 
especially  by  sudden  chilling  of  the  surface  of  the  body; 
consumption  therefore  was  to  be  regarded  as  brought  about 
in  the  same  way.  To  explain  why  all  who  were  subject  to 
exposure  did  not  fall  a  prey  to  the  disease  the  assumptions 
of  a  hereditary  predisposition  and  of  an  acquired  cachexia, 
or,  as  Flint  puts  it,  of  a  diathesis  whether  always  innate  or 
in  certain  cases  acquired,  became  necessary.  But  the  im- 
portant point  in  the  present  connection  is  that  the  prom- 
inence which  has  been  given  to  climate  as  a  curative  agent 
depended  primarily  upon  the  assumption  that  pulmonary 
tuberculosis  as  a  disease  of  the  lung  is  originally  caused  and 
is  influenced  in  its  progression  by  meteorological  influences 
like  the  other  diseases  of  the  lungs  the  most  conspicuous 
clinical  symptoms  of  which  are  cough  and  expectoration. 
Hence  the  use  of  cough  medicines  and  of  derivatives,  the 
warm  seat  by  the  fire,  the  window  tightly  closed  to  keep  out 
draughts. 

Joseph  A.  Gallup  in  Remarks  on  Pulmonary  Consumption 
which  are  appended  to  his  "  Sketches  of  Epidemic  Disease 
in  the  State  of  Vermont  from  its  first  settlement  to  the 
year  1815  "  expresses  the  opinion  that  conditions  of  hard 
labor  and  scanty  fare  do  not  produce  so  many  consumptions 
as  indolence  and  luxury.  Upon  the  same  principle,  he  says, 
much  riding  and  milk  diet  or  low  regimen  have  been  found 

1  Loo.  fit. 


THE   PRE-KOCHIAN  ERA  3 

useful  oftentimes  in  the  cure  and  prevention.  By  low 
regimen  Gallup  meant  bread  and  milk  alone  or  combined 
with  a  vegetarian  diet.  "  In  certain  very  low  states  how- 
ever and  also  after  hope  of  recovery  is  relinquished,  if  the 
patient  should  have  a  particular  desire  for  more  nourishing 
food  as  meat,  oysters,  etc.,  he  may  be  indulged."  Venesec- 
tion should  be  employed  more  or  less  extensively  according 
to  the  severity  of  the  case.  "  The  author  has  frequently 
treated  cases  of  phthisis  of  delicate  habit  by  bleeding  with 
advantage  beyond  his  most  sanguine  expectations."  After 
the  proper  curative  means  have  been  used  a  sufficient  length 
of  time  moderate  exercise  may  give  relief.  To  receive 
permanent  benefit  it  should  be  almost  constantly  employed 
even  to  the  point  of  fatigue.  This  heroic  treatment  was 
probably  about  the  same  as  that  which  the  author  would 
have  employed  in  gouty  bronchitis.  Evidently  he  conceives 
of  consumption  as  an  analogous  disease.  It  appears  from 
some  of  his  remarks  that  his  methods  had  received  criticism 
by  physicians  of  the  newer  school.  As  to  etiology  he  says : 
"  The  disease  appearing  chiefly  in  certain  districts  in  the 
same  latitude  gives  a  strong  presumption  that  some  dele- 
terious elementary  principle  is  necessary  to  its  production. 
Its  appearing  mostly  in  the  middle  latitudes  is  presumptive 
that  the  extreme  and  sudden  changes  of  temperature  from 
heat  to  cold  and  the  reverse  have  a  controlling  influence." 
We  may  paraphrase  this  somewhat  obscure  utterance  as 
follows:  Since  whatever  the  ultimate  cause  of  consump- 
tion may  be  the  disease  prevails  more  in  certain  districts 
than  in  others,  in  view  of  its  non-contagiousness  the  ob- 
served differences  as  to  prevalence  are  best  explained  by 
ascribing  them  to  meteorological  conditions.  But  con- 
sumption is  more  prevalent  in  the  temperate  zones  than 
elsewhere.    The  distinctive  characteristic  of  these  zones 


4  EPIDEMIOLOGY   OF  TUBERCULOSIS 

from  a  meteorological  point  of  view  being  a  wide  range  of 
temperature  with  rapid  alternations,  it  is  the  sudden 
changes  of  temperature  that  govern  the  appearance  of  the 
disease.  The  succinctness  of  the  author's  statement  of  his 
views  and  the  absence  of  argument  in  their  support  show 
that  he  believed  that  he  was  expressing  the  prevailing 
theory  of  his  day,  and  felt  no  need  of  explaining  in  what 
way  vicissitudes  of  temperature  could  have  so  serious  re- 
sults. Evidently  his  opinion  is  that  consumption,  like  other 
respiratory  diseases,  is  due  to  "  taking  cold." 

But  when  at  a  later  date  it  became  necessary  to  explain 
how  it  was  that  consumption  was  so  serious  a  disease  in  the 
mild  and  equable  temperature  of  the  South  Sea  Islands 
alternations  of  temperature  could  no  longer  be  advanced  as 
the  cause.  It  is  now  the  imprudence  of  the  sick  man  that 
is  to  be  blamed.  Gallup  would  never  have  dreamed  of  say- 
ing that  the  greater  prevalence  of  consumption  in  certain 
parts  of  the  United  States  was  due  to  the  fact  that  the 
inhabitants  of  those  districts  were  especially  careless  about 
wet  feet  or  about  sitting  in  draughts.  But  what  would 
have  been  absurd  if  said  of  a  homogeneous  people  in  whom 
a  certain  average  degree  of  prudence  is  to  be  assumed 
seemed  quite  in  place  when  applied  to  a  foreign  race  to  which 
the  author  holds  himself  superior.  Turner  writing  of  the 
Samoa  of  1868  says :  "  Chest  affections  of  all  kinds,  cough, 
asthma,  bronchitis,  phthisis,  etc.,  are  very  frequent.  This 
is  to  be  accounted  for  principally  by  the  extreme  careless- 
ness of  the  natives  sitting  down  right  in  a  strong  draught 
in  order  to  cool  off  or  exposing  themselves  to  the  injurious 
night  dews  which  are  so  heavy  in  these  islands."1  Rochard 
writing  in  1856  likewise  considers  chilling  of  the  body  a 


1  Notes  of  Practice  in  Samoa,  Glasgow  Med.  Jour.     Vol.  2,  4th  Series, 
1869-70,  p.  502. 


THE   PRE-KOCHIAN   ERA  5 

cause  of  consumption.  "  The  majority  of  deaths  at 
lahite,"  he  says,  "  are  due  to  pulmonary  phthisis  which 
kills  with  extraordinary  rapidity.  Its  ravages  among  the 
natives  are  explained  by  their  mode  of  life,  the  insufficiency 
of  their  clothing,  their  habitations  open  to  all  winds,  the 
abuse  of  cold  baths,  their  recklessness  when  ill  and  above 
all  their  incredible  libertinage."1  Another  medical  writer 
sets  himself  the  difficult  task  of  explaining  the  relative 
prevalence  of  tuberculosis  and  of  disease  in  general. 
Dutroulau-  in  his  works  published  in  1858  and  in  1868  on 
the  climatic  conditions  of  the  various  French  colonies  treats 
especially  of  the  effect  of  tropical  climates  upon  the  French 
of  the  military  and  naval  establishments  and  the  colonial 
civil  officials,  classes  which  are  admitted  into  colonial  hos- 
pitals and  figure  in  the  government  reports.  As  for  pul- 
monary tuberculosis  he  says,  rare  at  Senegambia  and 
Mayotte,  where  the  reign  of  epidemics  comprehends  all  the 
pathology,  it  figures  notably  in  the  statistics  of  all  the  other 
hospitals  and  there  is  no  medical  report  that  does  not  em- 
phasize the  fatal  influence  of  the  climate  upon  the  rapidity 
of  its  course.  For  him  the  more  or  less  sudden,  more  or 
less  great  variations  of  temperature  in  hot  countries  are 
only  the  accidents  of  meteorology  and  do  not  constitute  its 
pathological  action  which  resides  in  the  constant  elevation 
and  the  slight  variability  of  the  averages  (of  temperature, 
humidity,  etc.).  A  sense  of  suffocation  arises  from  the 
efforts  of  respiration  necessary  to  compensate  by  quantity 
for  the  lesser  oxygenation  of  the  air  inspired,  efforts  that 
result  in  fatigue  and  in  the  continual  excitation  of  the  pul- 
monary tissue,  that  is  to  say,  in  organic  debility  and  mor- 

1  Memoirs  de  FAeademie  de  Medecine.    Vol.  20,  1856,  p.  75. 

2  Traite  des  Maladies  des  Europeens  dans  les  Pays  Chauds.  Paris,  1868, 
p.  104.  Topographic  Medicare  des  Climats  Intertropicaux.  Paris,  1858. 
p.  120. 


6  EPIDEMIOLOGY   OF   TUBERCULOSIS 

bid  activity.  Let  there  be  some  perturbation  of  the  new 
functions  which  have  devolved  upon  the  skin  (as  from 
changes  of  temperature  we  will  suppose)  and  immediately 
the  effect  is  felt  in  the  internal  organs;  the  germs  of  dis- 
ease which  they  contain  receive  an  impulsion  which  hastens 
and  activates  their  symptomatic  explosion.  But,  he 
hastens  to  add,  the  fact  must  not  be  lost  sight  of  that  the 
physiological  modifications  in  the  functions  of  the  lung  and 
skin  are  due  to  the  elevation  and  non-variability  of  the 
meteorological  elements  much  more  than  to  their  variations. 
Otherwise  one  would  not  understand  why  in  Senegambia 
where  the  variations  of  humidity  and  of  temperature  are 
carried  to  an  extreme  pulmonary  tuberculosis  is  little  heard 
of  while  at  Cayenne  where  the  variations  are  imperceptible 
and  the  average  always  high  the  disease  develops  and  pro- 
gresses with  remarkable  rapidity.  Other  observers  may 
think  that  atmospheric  changes  are  the  cause  of  disease  but 
Dutroulau  evidently  prides  himself  on  his  ingenious  solu- 
tion of  the  problem :  "  Why  is  Cayenne  worse  for  con- 
sumption than  Senegambia  "  ?  and  specifically  calls  the  at- 
tention of  physicians  to  his  view  which  he  says  differs  from 
that  of  others.  The  difficulties  however  are  not  all  re- 
moved. He  had  given  humidity  as  one  of  the  causes  which 
really  underlie  the  pathology  of  tuberculosis.  Now 
Cayenne  is  one  of  the  most  humid  spots  in  the  world  while 
Senegambia  on  account  of  the  proximity  of  Sahara  is  rela- 
tively dry.  The  unwary  might  think  that  the  humidity  of 
Cayenne  accounted  for  its  inferiority,  certainly  in  these 
days  of  the  reign  of  bacteriology  that  is  what  we  should 
conclude.  But  the  ingenious  author  is  not  to  be  caught  so 
easily.  He  remembers  that  he  must  provide  for  the  fact 
that  the  heights  of  volcanic  islands  are  more  humid  and 
more   rainy   than   the  plains  but  nevertheless   are  more 


THE   PRE-KOCHIAN   ERA  7 

healthful,  which  he  says  they  owe  to  the  nature  of  their 
soil.  "  The  hygrometric  state  of  the  atmosphere  is  only  a 
direct  and  powerful  cause  of  insalubrity  in  relation  to  the 
geological  nature  of  the  soil ;  the  vapor  of  water  dissolves 
the  miasms."  With  the  aid  of  this  obscure  ally  every  path- 
ological situation  might,  it  would  seem,  be  explained,  but 
it  is  much  easier  to  frame  a  theory  that  will  account  for  the 
relative  healthfulness  of  two  countries  than  one  that  will 
fit  everywhere.  There  is  Cochin-China,  for  example,  to  be 
reckoned  with,  Cochin-China  which  he  says  seems  an  ex- 
ception to  all  rules.  For  there  it  is  not  the  wettest  time 
of  the  year,  when  (the  reader  would  suppose)  "  the 
miasms  "  would  be  dissolved  with  especial  facility  that  is 
the  most  unhealthful  but  the  second  quarter  when  the  rains 
are  just  commencing.  "  The  first  impregnation  of  the  soil 
by  the  waters  is  doubtless  the  cause  of  this  phenomenon, 
also  the  first  appearance  of  the  southwest  monsoon." 

Another  Frenchman  writing  at  about  the  same  time  as 
Dutroulau  was  reaching  very  different  conclusions.  Jour- 
danet1  had  to  account  for  the  fact  that  in  the  towns  of  Cam- 
peche  and  Merida  in  Yucatan  tuberculosis  is  an  acute  affec- 
tion which  kills  quickly  while  in  Tabasco  the  disease  is  rare. 
Now  Tabasco  lies  in  a  swampy  region  while  Campeche  and 
Merida  are  built  upon  a  dry  and  calcareous  soil.  Evidently 
then,  Jourdanet  thinks,  the  dry  and  calcareous  soil  must  be 
unfavorable  for  phthisis  and  he  fortifies  his  position  by  the 
statement  that  it  was  once  the  custom  to  send  the  phthisi- 
cal from  Campeche  and  Merida  to  Valladolid,  a  town  of  the 
interior  on  a  damp  site  and  surrounded  by  rank  vegetation, 
experience  having  shown  that  the  course  of  phthisis  was 
less  acute  there. 

The    foregoing   examples    illustrate    the    contradictions 

1Le  Mexique  et  1'AmGrique  Tropicale,  1864. 


8  EPIDEMIOLOGY   OF   TUBERCULOSIS 

which  result  when  general  conclusions  are  drawn  from  lim- 
ited observations  as  to  the  influence  of  climate. 

Hirsch1  is  the  most  prominent  early  systematic  writer  in 
the  domain  of  geographical  pathology.  The  second  volume 
of  the  first  German  edition  of  his  Handbook  was  published 
in  1862-1864.  He  recognizes  the  unsatisfactory  nature  of 
much  of  the  enormous  mass  of  data  that  he  had  collected 
and  the  unscientific  way  in  which  observations  as  to  the 
influence  of  climatic  conditions  upon  consumption  have 
been  made,  and  condemns  the  generalizations  which  are  so 
frequently  made  from  insufficient  data  as  fatal  for  the 
study  of  the  etiology.  If  one  would  throw  light  upon  this 
dark  subject,  he  says,  it  will  be  necessary  to  remember  that 
in  the  genesis  of  consumption  as  in  most  of  the  other  non- 
specific forms  of  disease  we  have  to  do  not  with  one  definite 
pathogenic  factor  but  usually  with  the  combined  action  of 
several  more  or  less  directly  pathogenic  factors.  The  mis- 
take of  over-emphasizing  one  factor  at  the  risk  of  under- 
estimating the  importance  of  the  others  is  made  by  those 
who  give  so  much  weight  to  purely  meteorological  condi- 
tions. Climate  can  not  be  the  essential  factor,  for  con- 
sumption has  appeared  in  many  localities  which  had  for- 
merly been  spared  without  there  having  been  any  change 
in  climatic  conditions.  The  mean  level  of  the  temperature 
has  no  significance  for  the  frequency  or  rarity  of  phthisis 
in  any  locality,  and  temperature-changes  are  important  only 
in  their  effect  upon  the  humidity  of  the  air;  they  have  no 
etiological  importance  when  the  air  is  absolutely  dry.  Just 
as  very  moist  air  is  an  important  causal  factor  in  catarrh 
and  bronchitis  so  also  is  it  for  consumption,  those  countries 
which  have  the  most  consumption  being  distinguished  by  a 


1  Handbuch  der  Historisch-geographisehen  pathologic     1st  German   Edi- 
tion, 1862-64,  Vol.  2,  p.  74. 


THE  PRE-KOCHIAN  ERA  9 

high  degree  of  humidity,  those  on  the  other  hand  which 
possess  an  immunity  from  the  disease  having  mostly  a  sur- 
prising dryness  of  the  air,  or,  with  average  moisture,  a 
very  equable  temperature.  Climate  and  weather  have  in- 
fluence upon  the  occurrence  or  the  geographical  extension 
of  tuberculosis  in  so  far  only  as  they  are  influential  in  pro- 
ducing directly  or  indirectly  more  or  less  continuous  and 
severe  irritation  of  the  respiratory  organs,  especially  the 
lungs,  as  the  result  of  which  there  first  appears  catarrhal 
affection  of  the  organ  which  with  continuance  of  the  nox- 
ious influence  becomes  a  locus  minoris  resistentiae  and, 
in  the  presence  of  a  predisposition  otherwise  induced,  a 
focus  of  the  morbid  process.  Elsewhere  he  says  summarily 
"  The  source  of  the  disease  is  to  be  sought  in  social  not  in 
meteorological  conditions."  The  predisposing  causes 
Hirsch  finds  in  denseness  of  the  population  to  which,  ceteris 
paribus,  the  frequency  of  tuberculosis  is  directly  propor- 
tional, further  in  sedentary  modes  of  life  with  the  resulting 
loss  of  exercise  and  of  fresh  air.  Uncivilized  people  when 
they  come  first  into  contact  with  Europeans  imitate  their 
mode  of  life  and  receive  physical  harm  by  so  doing.  Some 
races,  as  the  negro  race,  have  a  racial  predisposition.  He 
denies  that  the  geological  formation  or  the  character  of  the 
soil  has  any  importance  in  the  causation  of  tuberculosis. 

Consumption  then  in  his  definition  is  a  non-specific  dis- 
ease which  attacks  a  lung  already  damaged  by  injurious 
atmospheric  influences  provided  that  a  (very  ill-defined) 
predisposition  is  present,  which  predisposition  is  in  some 
way  connected  with  density  of  population  and  a  sedentary 
life.  Nothing  could  better  illustrate  than  this  definition 
the  difficulties  under  which  our  fathers  labored  in  their 
endeavor  to  account  for  the  course  and  dissemination  of 
tuberculosis  considered  as  a  non-infectious  disease. 


10  EPIDEMIOLOGY   OF  TUBERCULOSIS 

It  is  unfortunate  that  the  manner  in  which  tuberculosis 
comported  itself  when  first  introduced  among  an  absolutely 
uninfected  race  could  not  have  been  carefully  studied  by 
skilled  observers.  The  islands  of  the  Pacific,  on  account  of 
their  isolation,  would  have  been  peculiarly  favorable  places 
for  such  study.  But  the  first  dissemination  of  the  disease 
took  place  in  the  days  when  tuberculosis  was  not  believed 
to  be  infectious.  Captain  Cook  rediscovered  the  Sandwich 
Islands  in  1778  and  no  ship  has  visited  the  islands  of  the 
Pacific  since  his  day  that  has  not  borne  with  it  the  seeds  of 
disease  to  these  scattered  peoples,  who  are  probably  all  now 
more  or  less  infected  with  tuberculosis,  however  great  their 
isolation.  Naturally  no  ship  captain  thought  for  one  mo- 
ment of  such  a  danger,  and  if  it  had  ever  occurred  to  any 
one  of  them  as  a  possibility,  neither  he  nor  indeed,  for  that 
matter,  the  large  majority  of  the  physicians  of  the  present 
day  would  have  conceived  the  idea  of  danger  of  contagion 
from  the  healthy  members  of  the  crew  who  were  bacillus- 
carriers,  while  no  articles  given  in  barter  would  have  been 
considered  potential  sources  of  infection  unless  they  were 
known  to  have  been  used  by  a  consumptive.  So  that  what- 
ever other  infections  they  may  have  bestowed  no  doubt  the 
crews  of  the  ships  that  had  left  the  fatal  gift  of  tubercu- 
losis sailed  away  with  a  perfectly  clear  conscience  so  far  as 
that  disease  was  concerned.  Of  course  early  visitors  to  the 
tropics  soon  noted  that  consumption  did  not  prevail  among 
the  natives.  Hence  the  natural  inference  that  since  the 
disease  was  due  to  climatic  influences,  the  climate  of  the 
place  which  showed  so  singular  an  immunity  would  be  bene- 
ficial for  those  who  were  already  affected  with  it.  As  a 
result  of  this  view  European  consumptives  were  encouraged 
to  visit  the  tropics  in  order  to  reap  the  advantages  of  the 
climatic  conditions.     The  Catholic  sisters  in  the  French 


THE   PRE-KOCHIAN   ERA  11 

Congo,  for  example,  imported  from  Europe  many  of  their 
order  who  had  tuberculosis  in  the  hope  of  curing  them.  But 
the  results  of  this  experiment,  according  to  Gamier,  were 
disastrous.1  When  in  later  years  the  disease  had  become 
disseminated  through  the  native  populations,  on  account  of 
the  prevailing  view  of  its  non-communicability  the  facts 
were  necessarily  interpreted  not  as  an  evidence  of  the  infec- 
tiousness of  tuberculosis  but  as  showing  that  the  former 
observation  as  to  its  absence  must  have  been  erroneous.  It 
may  appear  singular  at  first  sight  to  one  who  reads  Dutrou- 
lau's  works  that  he  considers  only  the  European  colonist 
in  his  studies  of  the  relation  of  tropical  climates  to  the  inci- 
dence of  tuberculosis.  But  from  his  standpoint  this  was 
the  scientific  way  of  approaching  the  subject,  for  whatever 
particular  meteorological  conditions  might  be  given  the 
chief  blame  for  inducing  consumption  Europeans  and  na- 
tives were  equally  exposed  to  them,  with  the  advantage  on 
the  side  of  the  natives  of  better  acclimatization,  while  sta- 
tistics were  only  available  for  the  Europeans.  Doubtless 
many  early  cases  of  primary  tuberculosis  failed  of  recogni- 
tion as  such,  for  acute  tuberculosis  is  not  easy  of  diagnosis. 
Finally  however  it  became  impossible  to  disguise  the  fact 
that  tuberculosis  of  the  lungs  was  making  serious  inroads 
upon  the  native  population,  and  that  the  type  of  the  disease 
was  very  fatal  and  relatively  acute.  The  conclusion  drawn 
from  this  was  of  course  that  Europeans  were  exposed 
equally  with  the  native  to  the  dangers  of  infection  with  a 
particularly  deadly  type  of  this  disease,  and  the  warning 
was  given  by  Rochard  that  European  consumptives  should 
not  be  sent  to  the  tropics  however  mild  and  apparently  in- 
viting the  climate.     As  he  put  it,  "  the  countries  of  the 

aLa   tuberculose   au  Congo   Franeais.     Ann.    d'Hyg.    et    de   Med.   Colon. 
Vol.  6;  p.  306. 


12  EPIDEMIOLOGY   OF   TUBERCULOSIS 

torrid  zone  are  divided  into  two  classes:  in  the  one  the 
countries,  such  as  Senegambia,  India  and  Madagascar,  are 
so  unhealthful  that  one  could  not  think  of  sending  patients 
to  them;  the  other  class,  countries  which  invite  confidence 
by  the  mildness  of  their  climate,  are  the  places  where 
tuberculosis  advances  most  rapidly."1 

1  Loc.  cit. 


CHAPTER  II 
THE  MODERN  ERA 

The  momentous  discovery  of  Koch  proved  that  the  tu- 
bercle bacillus  is  the  cause  of  tuberculosis  and  that  there- 
fore the  disease  is  infectious.  Climatic  conditions  will 
cease  henceforth  to  play  the  chief  role  in  the  etiology  of 
tuberculosis  and  pulmonary  tuberculosis  will  no  longer  be 
regarded  as  a  disease  of  the  lungs  simply.  It  was  only 
natural  that  the  infectiousness  of  tuberculosis  should  come 
into  the  foreground,  but  the  doctrine  was  carried  too  far. 

The  physicians  of  the  former  generations  were  good 
observers.  In  fact  they  were  better  observers  than  we  are 
because  they  could  not  depend  upon  the  bacteriological  or 
the  roentgenological  laboratory  for  help  in  diagnosis.  The 
view  of  the  practitioner  had  been  that  consumption  was  not 
a  communicable  disease,  and  this  view  was  based  collec- 
tively upon  an  enormous  experience.  But  when  it  became 
known  that  tuberculosis  was  due  to  an  infection  the  medical 
authorities  instead  of  pausing  to  inquire  what  there  might 
be  of  truth  in  so  universal  an  opinion  simply  threw  over- 
board the  experience  of  past  generations  and  proclaimed 
that  all  persons,  irrespective  of  age,  were  susceptible  to 
tuberculous  infection  from  contact  direct  or  indirect  with 
the  consumptive,  an  assumption  that  governs  to-day  the 
program  of  practical  tuberculosis  prophylaxis,  to  say  noth- 
ing of  the  opinion  of  the  medical  profession. 

Of  course  universal  susceptibility  did  not  mean  universal 
infection,  for  only  a  minority  of  the  population  develops 
clinical  tuberculosis.  To  explain  the  escape  of  the  majority 
it  was  necessary  to  take  recourse  to  the  old  doctrine  of  pre- 
disposition.   Of  all  who  are  exposed  to  the  infectious  agent 

13 


14  EPIDEMIOLOGY   OF  TUBERCULOSIS 

only  those  will  fall  sick  whose  resistance  is  low,  for  various 
reasons.  But  it  is  possible  (this  is  the  distinguishing  fea- 
ture of  the  doctrine)  for  every  individual  to  become  in- 
fected from  without  provided  that  his  resistance  is  suffi- 
ciently reduced.  The  predisposing  factors  were  admittedly 
obscure  in  many  cases,  but  in  general,  aside  from  the  pos- 
sibility of  racial  and  hereditary  predisposition,  amounted 
practically  to  conditions  that  tend  to  impair  the  health. 
Hence  was  derived  the  proposition :  Good  health  prevents 
the  infection  of  tuberculosis  from  taking  hold. 

If  we  seek  analogies  in  justification  of  this  position 
we  shall  find  that  the  escape  of  the  healthy  when 
exposed  to  infection  from  the  virus  of  dangerous  dis- 
ease is  due  either  to  the  smallness  of  the  infecting 
dose  or  to  the  fact  that  the  subject  has  already  had 
the  disease  and  has  thereby  acquired  an  immunity.  But  in 
the  case  of  tuberculosis  there  appears  to  be  no  relation 
between  the  size  of  the  infection  and  the  development  of 
clinical  disease.  Those  who  are  most  constantly  exposed, 
the  physicians  and  nurses  of  tuberculosis  hospitals,  the 
laryngologists,  the  mothers  and  wives  of  the  consumptives 
do  not  show  a  higher  incidence  of  tuberculosis  than  the 
remainder  of  the  population.  On  the  other  hand  the  dis- 
ease often  attacks  persons  whose  life  has  been  most  care- 
fully shielded  and  who  have  not  been  known  to  have  had 
any  opportunity  for  infection  —  cases  in  which  at  least 
there  has  been  no  possibility  of  large  and  repeated  infec- 
tions. Under  the  complicated  conditions  of  modern  life  it 
is  usually  possible  to  find  evidence  of  contact  more  or  less 
remote  with  cases  of  tuberculosis  which  satisfy  some  epi- 
demiological writers  as  identifying  the  modes  of  transmis- 
sion of  infection. 

To   get   at   the   real    facts   we   should   turn    to    classes 


THE  MODERN  ERA  15 

of  cases  in  which  the  mode  of  life  and  the  oppor- 
tunities for  infection  have  been  under  close  observation. 
Nuns  immured  in  convent  cells  are  especially  prone  to  be- 
come tuberculous.  The  same  is  true  of  prisoners,  and,  it 
appears,  those  in  solitary  confinement  are  more  subject  to 
tuberculosis  than  other  prisoners.  Fraenkel1  quotes  Baers, 
an  experienced  prison-physician,  who  says :  "  The  great 
frequency  of  phthisis  among  prisoners  can  not  be  explained 
alone  by  direct  infection  by  the  bacilli  in  the  air  from  the 
sputum  of  the  tuberculous."  Fraenkel  concludes  that  many 
prisoners,  not  by  any  means  only  the  pronounced  consump- 
tives, bring  with  them  the  germ  of  their  disease  into  the 
prison.  In  such  cases  then  the  predisposing  causes  act  not 
to  produce  infection  but  to  make  latent  infection  manifest 
disease. 

Hirsch  expressed  the  opinion  that  the  frequency  of  tuber- 
culosis is  directly  proportional  to  the  density  of  the  popula- 
tion. But  the  interesting  fact  developed  in  the  last  quarter 
of  the  19th  century  that  the  mortality  rate  from  tubercu- 
losis was  diminishing  in  the  greater  part  of  the  civilized 
countries  of  Europe  and  America,  and  that  too  for  the  most 
part  in  the  very  countries  in  which  the  population  was 
becoming  more  dense.  Nor  could  it  be  said  that  there  had 
been  any  very  general  improvement  in  these  countries  as 
to  the  sedentary  mode  of  life  and  loss  of  exercise  and  of 
fresh  air  which  Hirsch  apparently  regards  as  the  harmful 
results  of  the  density  of  population.  Tuberculosis  workers 
would  have  been  glad  to  ascribe  this  unexpected  ameliora- 
tion to  the  newly  instituted  prophylaxis  against  tubercu- 
losis. But  the  facts  did  not  bear  out  this  view.  In  the 
first  place,  the  improvement  began  before  the  discovery  of 
the  tubercle  bacillus;    in   the    second,  while  the  mortality 

XA.  Fraenkel,  Pathologie  und  Therapie  der  Lungenkrankheiten,  p.  761. 


16  EPIDEMIOLOGY   OF  TUBERCULOSIS 

rate  had  diminished,  the  morbidity  rate  had  not.  As 
many  cases  of  tuberculosis  occurred  as  before  proportion- 
ally to  the  population,  not  as  many  died.  Infection  oc- 
curred as  before,  there  was  therefore  no  change  in  the 
tubercle  bacillus ;  the  improvement  must  be  due  then  either 
to  diminution  in  the  size  of  infections  or  to  increased  resist- 
ance on  the  part  of  the  infected  individual.  It  appeared 
further  that  the  improvement  in  the  tuberculosis  mortality 
was  associated  with  a  like  improvement  in  the  general  mor- 
tality. In  other  words,  the  general  health  of  the  com- 
munity was  improving  and  with  it  the  situation  as  to  tuber- 
culosis. The  improvement  in  the  general  health  was  no 
doubt  rightly  ascribed  to  various  measures  of  sanitation 
and  to  ameliorations  of  the  conditions  of  life,  some  of  which 
might  be  considered  to  have  lessened  the  opportunities  for 
massive  tuberculous  infections,  but  which  in  general  were 
not  directed  specifically  against  the  tubercle  bacillus.  We 
see  then  that  at  least  in  some  cases  changes  in  hygiene  both 
for  good  and  for  ill  exert  their  effect  not  to  prevent  or 
facilitate  infection,  but  to  influence  the  manner  in  which 
the  already  tuberculous  individual  reacts  to  the  disease. 
By  the  morbidity  of  tuberculosis  is  meant  the  number  of 
cases  of  manifest  tuberculous  disease.  It  has  been  learned 
of  late  years  that  the  number  of  individuals  who  can  be 
shown  by  radiography,  tuberculin  tests  and  autopsy  find- 
ings to  have  some  focus  of  tuberculosis  is  enormously  in 
excess  of  those  who  are  usually  classed  as  tuberculous,  in 
fact  that  tuberculous  infection  is  well-nigh  universal  in  our 
civilization.  This  fact  gives  a  new  significance  to  the 
latency  of  the  tubercle  bacillus  and  leads  us  to  inquire 
whether  it  is  correct  to  assume  that  when  infection  has 
occurred  the  tuberculosis  of  the  adult  declares  itself  imme- 
diately or  after  a  brief  incubation  or  whether  it  is  not  more 


THE  MODERN  ERA 


17 


probable  that  the  period  of  latency  may  be  indefinitely  pro- 
longed, so  that  everything  that  makes  for  good  health  not 
only  helps  the  already  tuberculous  patient  in  prolonging  his 
life  or  even  in  arresting  his  disease,  but  is  operative  as  well 
m  the  protection  against  manifest  tuberculosis  of  a  vast 
body  of  individuals  who  are  infected  but  whose  infection 
remains  latent. 

Ranke  remarked  in  1910:  "  General  hygienic  measures, 
above  all  in  the  construction  of  dwellings  and  in  canalisa- 
tion, and  the  raising  of  the  average  income  of  the  working 
man,  have  reduced  the  mortality  from  phthisis  of  the  Ger- 
manic countries  to  an  extraordinary  degree.  It  is  surpris- 
ing that  during  the  same  period  there  has  been  either  no 


•^tsi   i/n     ^  Ov  ?i 

J  »      i       *  **  "^ 

**<  o  4       A       i 


Chart  No.  1 


Chart  No.  1. —  The  mortality  from  phthisis  and  from  generalized  tuber- 
culosis per  100,000  living  at  the  various  ages  in  Bavaria  for  the  year 
1905. 

Generalized  tuberculosis     . 


18  EPIDEMIOLOGY  OF  TUBERCULOSIS 

diminution,  or  but  slight  diminution,  of  the  mortality  from 
the  tuberculosis  of  children.  In  some  states  indeed  it  has 
increased  of  late."1 

The  tuberculosis  of  early  childhood  is  the  result  of  a 
recent  infection  with  tubercle  bacilli.  It  is  therefore  prac- 
tically a  primary  tuberculosis.  Now  fatal  primary  tuber- 
culosis reveals  itself  at  autopsy  as  a  generalized  disease. 
Even  when  the  case  has  been  classed  as  pulmonary  tuber- 
culosis under  the  rule  that  all  cases  will  be  called  pulmonary 
tuberculosis  in  which  the  lungs  participate  to  any  consider- 
able degree  in  the  disease,  at  this  age  the  disease  is  really 
generalized  tuberculosis —  entirely  different  as  to  prog- 
nosis, clinical  course  and  anatomical  findings  from  the 
phthisis  of  the  adult.  Chart  No.  1  shows  the  curves  of  mor- 
tality in  Bavaria  for  the  year  1905,  the  curve  with  heavy 
line  representing  the  mortality  from  phthisis  and  the  one 
with  the  thin  line  that  from  generalized  tuberculosis,  the 
horizontal  lines  denoting  years  of  life,  the  vertical  the 
ratios  of  mortality  per  100,000  living  at  the  different  ages. 

It  will  be  noted  that,  as  Ranke,  from  whose  article  the 
chart  is  taken,  remarks,  the  two  forms  of  tuberculosis 
appear  two  absolutely  different  diseases.  That  generalized 
tuberculosis  is  indeed  governed  by  different  laws  from 
those  of  phthisis  is  shown  by  the  fact  that  the  mortality  is 
not  influenced  by  improvements  in  the  conditions  of  life 
which  have  been  instrumental  in  lowering  to  such  a  remark- 
able extent  the  mortality  from  phthisis. 

This  is  shown  in  a  graphic  way  by  Chart  No.  2,  also 
taken  from  Ranke,  which  gives  the  ratios  per  100,000  liv- 
ing at  the  different  ages  of  the  total  mortality  from  tuber- 
culosis in  Bavaria  for  the  years  1876,  1889  and  1902.  It 
will  be  noted  that  there  is  an  enormous  fall  of  the  curve  at 


'Archiv  filr  Kinderheilkunde.     Vol.  54,  1910,  p.  279. 


THE  MODERN  ERA 


19 


its  peak  at  the  age  of  65,  but  hardly  any  change  in  the  mor- 
tality before  the  5th  year  of  life. 

From  the  report  of  Colonel  E.  H.  Brims,  U.  S.  A.,  upon 
the  tuberculosis  situation  in  Germany  it  appears  that  dur- 
ing the  war  there  has  been  a  marked  increase  in  tubercu- 
losis, which  has  been  proportionately  greater  in  the  cities 


«!|||[H|iii 

1  1 

a. :.. 

22 

1 1  s 

.+            •'' 

i  V 

»  i 

^                    » t 

•""''.'''-'''                     ,,.-''' 

vs              \  \ 

1 

j) ,.  ■'  "1 

..-'-''" 

\        \ 

-i 

W/ 

..............                    i 

o^ail 

•<p? 

O             5          K 

IS          £}          S 

i          30           3S           *>           V            SO          S. 

r         SB        6S        10        75        so}. 

Chart  No.  2 

Chaet  No.  2. —  The  mortality  from  all  forms  of  tuberculosis  per  100,000 
living  at  various  ages  in  Bavaria  in  the  years  1876,  18S9  and  1902. 


than  in  the  smaller  towns  and  in  the  country.1  This  in- 
crease is  probably  correctly  ascribed  to  deficiency  of  food 
which  would  naturally  be  more  marked  in  the  cities  than  in 
the  country,  where  the  inhabitants  could  produce  a  portion 
of  their  food-supplies.2  The  death-rate  from  tuberculosis 
per  100,000  of  population  in  Trier  (Treves)  increased  from 
204.1  in  1913,  to  364.1  in  1918,  and  in  Coblenz  the  rates 

*The  Tuberculosis!  Situation  in  Germany.  Unpublished  report  to  the 
Surgeon  General,  U.  S.  Army. 

2  But  in  England  where  there  has  been  little  cause  to  complain  of  lack 
of  food,  there  has  been  a  similar  rise  in  the  mortality  from  tuberculosis. 


20 


EPIDEMIOLOGY   OF  TUBERCULOSIS 


were  100.8  and  191.5  for  the  same  periods.  In  Cologne  the 
death-rate  per  million  for  pulmonary  tuberculosis  was  1385 
in  the  period  1910-1913  inclusive,  and  2190  for  the  period 
1914-1918.  For  tuberculosis  of  other  organs  it  was  363 
and  505  and  for  miliary  tuberculosis  43.1  and  43.5  respec- 
tively for  the  same  periods.  Chart  No.  3  gives  the  curve 
of  the  death  rates  for  various  ages,  ft  is  taken  from  the 
Statistisches  Jahrbuch  der  Stadt  Koln  1919. 


6oct- 


S06 


I 

^  40 >oU 


Aql  Psxtoo  I 


Deoth  Rotes  per  Mittion  Alt Afes 

Year* 

/S/0-/J 

I9HH 

luno  Tuberculoih 

J38S 

2J90 

Other  Organs 

J63. 

Jos 

Milhrt/  Tukerculos/s, 

431 

4JS 

Chart  No.  3 

Chart  No.  3. —  The  mortality  from  pulmonary  tuberculosis,  tuberculosis 
of  other  organs  and  miliary  tuberculosis  per  million  living  in  Cologne, 
Germany,  before  and  during  the  war. 


Pulmonary  tuberculosis, 
Tuberculosis,  other  organs, 
Miliary  tuberculosis, 


1910-1913  incl.  -+-  -+-  -+-,  1914-1918  incl.  —  |  —  |— 

1910-1913  incl. — ,  1914-1918  incl. 

1910-1913,  incl. ,  1914-1918  incl. 


This  chart  shows  very  clearly  that  the  difference  be- 
tween the  two  periods  is  very  marked  as  to  pulmonary 
tuberculosis,  distinct  as  to  tuberculosis  of  other  organs  and 


THE  MODERN  ERA  21 

practically  non-existent  as  respects  miliary  tuberculosis. 
Now  miliary  tuberculosis  is  the  form  that  characterizes 
above  all  other  forms  of  the  disease  the  primary  infection. 
If  individuals  of  all  ages  in  Germany  were  susceptible  to 
primary  tuberculous  infection  and  if  predisposition  to  pri- 
mary infection  were  increased  by  depressing  influence  such 
as  semi-starvation  or  improper  diet,  the  increase  from  war 
conditions  would  be  most  marked  in  this  type  of  the  dis- 
ease, but  on  the  contrary  it  is  precisely  the  most  chronic 
type  of  tuberculosis  which  shows  the  greatest  increase  in 
mortality. 

It  is  commonly  taught  that  the  acute  miliary  tuberculosis 
of  the  adult  is  secondary  to  an  old  tuberculous  lesion  and 
that  it  depends  typically  upon  the  irruption  into  the  blood- 
stream of  the  contents  of  a  softened  lymph-gland  which  is 
adherent  to  the  sheath  of  a  bloodvessel.  This  pathological 
accident  transforms  the  situation  with  startling  rapidity. 
The  subject  dies  of  acutest  tuberculosis  who,  though  his 
disease  was  not  progressing  altogether  favorably,  might  yet 
without  such  an  accident  have  escaped  clinically  manifest 
tuberculosis  altogether  or  might  have  figured  among  the 
cases  of  phthisis  at  a  more  advanced  age. 

If  we  turn  to  Chart  No.  1,  we  will  note  that  the  curve  of 
generalized  tuberculosis  after  the  age  of  three  years  is 
represented  by  a  dotted  line  until  the  age  of  sixteen  years  is 
reached;  that  is,  there  are  no  deaths  (or  not  a  sufficient 
number  of  deaths  to  be  plotted)  from  generalized  tubercu- 
losis between  the  ages  of  three  and  sixteen  years.  Simi- 
larly, the  curve  for  the  phthisis  mortality  is  shown  as  a 
dotted  line  up  to  the  age  of  sixteen  —  there  is  no  typical 
phthisis  until  that  age  is  reached.  Of  course,  while  the 
period  from  three  to  sixteen  years  is  the  period  of  life  in 
which  the  tuberculosis  mortality  is  lowest,  there  are  never- 


22  EPIDEMIOLOGY   OF   TUBERCULOSIS 

theless  deaths  from  tuberculosis  —  a  tuberculosis  prepon- 
deratingly  more  chronic  than  the  acute  generalized  form 
of  earlier  years,  but  one  that  is  not  yet  confined  to  the  lungs 
as  is  genuine  phthisis,  comprising  what  is  denoted  in  Chart 
No.  3  "  tuberculosis  of  other  organs,"  but  including  many 
cases  in  which  the  lungs  are  involved.  We  know  from  the 
von  Pirquet  reaction  that  children  of  the  fourth  and  imme- 
diately succeeding  years  do  not  yet  show  high  percentages 
of  sensitiveness  to  tuberculin.  It  is  commonly  assumed 
that  negative  cases  at  this  age  are  not  yet  infected.  It  is 
a  significant  fact,  however,  that  such  children,  if  they 
die  at  all  from  tuberculosis,  usually  die  of  forms  which  are 
characteristic  of  an  immunization  —  one  that  is  imperfect 
because  but  recently  acquired,  yet  sufficiently  marked  to 
lend  a  character  of  chronicity  to  the  disease.  The  compara- 
tive absence  of  the  generalized  type  can  not  be  explained  on 
grounds  of  greater  maturity  alone,  for,  as  we  shall  see, 
adults  may  die  of  acutest  primary  tuberculosis  if  not  pro- 
tected by  a  previous  infection.  The  facts  lead  us  to  sus- 
pect that  children  may  often  receive  a  tuberculous  infection 
at  an  earlier  age  than  that  which  seems  to  be  fixed  by  the 
skin  test,  there  seeming  to  be  some  grounds  for  the  belief 
that  the  von  Pirquet  reaction  is  sometimes  negative  even  in 
young  children  when  tuberculous  infection  is  undoubtedly 
present.  Secondary  generalized  tuberculosis  begins  to 
show  itself  in  Chart  No.  1  in  the  mortality  ratios  in  the 
same  year  of  life  that  marks  the  beginning  of  deaths  from 
phthisis.  The  mortality  from  generalized  tuberculosis  ex- 
tends as  a  nearly  straight  line  throughout  the  years  of  life. 
It  does  not  follow  the  curve  of  the  phthisis  mortality  for 
the  different  ages  nor,  as  Chart  No.  3  shows,  is  it  affected 
by  the  causes  that  lead  to  an  increase  in  the  mortality  from 
phthisis.     As  a  "  pathological  accident "  it  is  related  to  the 


THE  MODERN  ERA  23 

tuberculous  infection  of  the  population.  In  other  words,  a 
certain  percentage  of  all  living  at  the  various  ages  of  adult 
life  (for  after  the  age  of  sixteen  all  Bavarians  may  be 
assumed  to  have  become  infected  with  tuberculosis)  are 
doomed  to  die  of  miliary  tuberculosis  because  they  have  a 
softened  gland  adherent  to  a  bloodvessel,  or  for  some  other 
more  obscure  reason. 

Chart  No.  3,  which  does  not  take  into  account  the  tuber- 
culosis of  infancy,  shows  miliary  tuberculosis  to  begin 
about  the  age  of  five  years  and  to  continue  throughout  the 
years  of  life  at  about  the  same  level.  The  distinction  be- 
tween primary  and  secondary  miliary  tuberculosis  is  not 
apparent  here,  and  evidently  no  distinction  is  made  between 
the  pulmonary  tuberculosis  of  childhood  and  the  phthisis  of 
the  adult.  But  it  is  not  necessary  to  attempt  to  reconcile 
the  two  charts  nor  wise  to  draw  too  strict  conclusions  from 
slight  differences  in  curves  that  are  designed  to  show  in  a 
general  way  the  sweep  of  the  disease  over  a  large  popula- 
tion. The  charts,  however,  show  clearly  enough  that  the 
forms  of  tuberculosis  that  are  less  localized  than  phthisis 
but  more  chronic  than  acute  miliary  tuberculosis  are  much 
more  prevalent  in  childhood  than  in  later  years,  declining 
very  rapidly  at  the  period  of  adolescence,  when  tuberculiza- 
tion is  becoming  well-nigh  universal  and  that  the  curves 
representing  these  forms  are  less  affected  than  is  phthisis 
by  either  improvement  (Chart  No.  2)  or  deterioration 
(Chart  No.  3)  in  the  conditions  of  existence.1 

JThe  difference  as  to  the  age-periods  at  which  the  peak  of  the  tuber- 
culosis mortality  is  reached  which  will  be  noted  in  Charts  Nos.  1  and  2,  as 
compared  with  Chart  No.  3,  is  due,  of  course,  to  the  fact  that  in  these 
charts  the  ratio  is  that  of  the  number  of  deaths  from  pulmonary  tuber 
culosis  at  each  age  to  the  number  of  persons  living  at  that  age,  showing 
the  highest  mortality  at  about  the  age  of  sixty-five,  while  in  Chart  No.  3 
deaths  from  pulmonary  tuberculosis  at  the  various  ages  are  compared  with 
the  number  living  at  all  ages,  the  greatest  absolute  number  of  deaths  tak- 
ing place  between  the  ages  of  twenty  and  thirty. 


24  EPIDEMIOLOGY   OF  TUBERCULOSIS 

We  may  say  then  that  the  mortality  from  tuberculosis  is 
divided  into  three  classes  as  respects  age  and  type  of  dis- 
ease: first,  the  acute  generalized  primary  tuberculosis  of 
infancy;  second,  the  more  chronic  but  still  not  well  local- 
ized tuberculosis  of  childhood  (a  miscellaneous  classification 
including  disease  of  bones,  joints  and  glands  as  well  as 
tuberculosis  of  more  than  one  viscus)  ;  third,  the  well  local- 
ized pulmonary  tuberculosis  or  phthisis  of  the  adult  with 
the  "  pathological  accident "  of  secondary  miliary  tubercu- 
losis to  account  for  a  small  percentage  of  deaths.  The  vari- 
ations in  the  mortality  of  the  tuberculosis  of  civilized  com- 
munities which  are  effected  by  changes  good  or  bad  in  the 
hygienic  conditions  are  variations  almost  entirely  of 
chronic  pulmonary  tuberculosis.  Less  well  localized  but 
still  relatively  chronic  forms  of  tuberculosis  are  somewhat 
affected,  acute  primary  forms  and  miliary  tuberculosis  in 
general  are  practically  uninfluenced  by  such  changes.  In 
other  words,  to  speak  broadly,  primary  tuberculosis  be- 
haves like  an  infectious  disease,  chronic  tuberculosis  does 
not. 

With  reference  to  the  question  of  the  duration  of  tuber- 
culous infection  before  the  development  of  manifest  tuber- 
culous disease  a  comparison  of  tuberculosis  with  typhoid 
fever  may  be  instructive.  In  the  latter  disease  large  infec- 
tions take  hold  very  generally  upon  those  not  protected  by 
previous  attacks  of  the  disease  without  regard  to  the  health 
of  the  subjects.  But  of  a  number  of  susceptible  persons 
who  are  equally  exposed  to  lighter  infections  not  all  will 
fall  sick,  some  may  appear  to  escape  entirely.  Here  it 
would  be  correct  to  say  that  good  health  enables  some  to 
resist  the  infection  with  entire  success.  Often,  especially 
in  military  practice,  there  may  appear  to  be  but  little  or  no 
typhoid  fever  in  a  group  of  individuals  until  they  are  ex- 


THE  MODERN  ERA  25 

posed  to  conditions  of  especial  fatigue  or  hardship,  when 
such  large  numbers  fall  sick  at  the  same  time  that  it  would 
seem  probable  that  the  outbreak  of  the  disease  is  due  to  the 
simultaneous  exposure  to  depressing  influences  of  men 
already  harboring  the  typhoid  bacillus  rather  than  to  an 
immediately  preceding  infection.  A  change  in  the  predis- 
position  has  thus  caused  an  outbreak  of  a  disease  which 
though  previously  entirely  latent  for  a  longer  or  shorter 
time  is  nevertheless  an  acute  disease.  We  may  say  then 
that  the  question  whether  a  comparatively  slight  infection 
with  the  typhoid  bacillus  shall  result  in  manifest  disease  or 
not  is  determined  by  the  resistance  of  the  subjects. 

This  is  the  way  in  which  tuberculous  infection  is  also 
commonly  conceived  of.  Tubercle  bacilli,  incorporated  in 
some  way  by  persons  previously  uninfected,  in  a  brief  time 
if  predisposition  exists  are  supposed  to  produce  a  tubercu- 
lous infection,  though  this  as  a  matter  of  fact  generally 
manifests  itself  as  a  chronic  pulmonary  tuberculosis.  But 
if  there  is  no  predisposition  to  tuberculosis,  the  individuals 
concerned  remain  perfectly  healthy,  escaping  entirely  the 
exposure  in  question.  That  is,  in  this  view  there  is  either 
rather  quickly  manifest  tuberculosis  as  the  result  of  the 
exposure  to  infection  or  no  tuberculosis  at  all.  In  other 
words,  as  in  acute  infectious  disorders,  the  infection  is 
expected  to  declare  itself  with  little  delay  and  if  it  does  not 
do  so,  the  transaction  is,  as  it  were,  closed. 

But  the  tubercle  bacillus  is  admittedly  a  micro-organism 
which  is  long-lived  and  difficult  to  kill  and  which  often 
causes  extremely  chronic  types  of  disease.  We  will  sup- 
pose then  that  the  tubercle  bacillus  is  like  the  typhoid  bacil- 
lus in  that  when  infecting  in  large  numbers  it  causes  an 
acute  general  disease  but  that  when  its  infections  are  small 
the  result  may  be  a  latency   (or  obscure  activity)   which 


26  EPIDEMIOLOGY   OF  TUBERCULOSIS 

resembles  that  of  the  typhoid  bacillus,  conditions  of  health 
in  either  case  determining  whether  or  not  the  latency  shall 
be  transformed  into  manifest  active  disease. 

But  in  consideration  of  the  fact  that  the  tubercle  bacillus 
is  more  sluggish  and  resistant  than  the  typhoid  bacillus  we 
may  also  suppose  that  the  latency  that  is  not  conspicuous 
nor  easily  determined  in  the  case  of  the  typhoid  bacillus 
characterizes  the  tubercle  bacillus  much  more  frequently 
and  that  if  after  infection  no  disease  declares  itself  the 
presumption  is  not  that  the  tubercle  bacillus  has  been  de- 
stroyed as  are  less  resistent  bacteria  but  that  it  continues 
to  live  for  an  indefinite  period.  Moreover  it  is  a  fact  that 
the  tubercle  bacillus  when  it  has  entered  the  organism  does 
not  lead  a  precarious  existence  as  a  saprophyte  in  the  respi- 
ratory passages  or  in  the  alimentary  canal  but  by  virtue 
of  the  mysterious  properties  of  its  pathogenicity  is  enabled 
to  penetrate  the  tissues  and  maintain  itself  there.  Unless 
the  tubercle  bacillus  differs  from  all  other  infectious  organ- 
isms we  must  go  on  therefore  to  assume  that  there  are 
interrelations  between  the  bacillus  and  the  human  organ- 
ism, that  each  must  adapt  itself  to  the  other  but  that  in 
such  mutual  adaptations  the  intensively  alive  and  enor-' 
mously  complicated  organism  of  man  will  go  farther  in 
modifying  its  activities  than  its  enemy,  a  microscopic  bit 
of  poisoned  wax.  Under  such  supposed  conditions  where 
the  contest  is  of  indefinite  duration  it  is  evident  that  exter- 
nal conditions  which  make  for  health,  while  they  do  not  and 
could  not  be  expected  to  exert  any  marked  influence  upon 
the  actual  reception  into  the  tissues  of  an  enemy  so  capable 
of  penetration,  will  have  much  influence  in  preventing 
latency  from  transforming  itself  into  activity.  With  this 
supposition  then  what  has  been  called  predisposition  to  in- 
fection becomes  the  sum  of  influences  unfavorable  to  resist- 


THE  MODERN  ERA  27 

ance  to  already  acquired  infection.  The  value  of  good  sani- 
tation now  becomes  enormously  heightened  because  it  is  no 
longer  simply  called  upon,  as  in  the  theory  of  predisposi- 
tion to  make  an  effort  once  for  all  to  destroy  an  acutely 
infecting  bacillus,  but  is  to  exert  its  influence  through  many 
years,  indeed  through  life,  to  aid  in  the  long  struggle 
against  an  entrenched  enemy.  We  are  no  longer  compelled 
to  admit  the  absurd  view  that  a  supposedly  known  recent 
infection  results  in  a  chronic  benign  pulmonary  tuberculo- 
sis. And  we  are  no  longer  involved  in  the  difficulties  which 
arise  when  we  attempt  to  explain  the  enormous  difference 
which  exists  between  the  chronic  pulmonary  tuberculosis 
of  the  adult  and  the  acute  generalized  tuberculosis  of  the 
infant.  With  the  old  view  the  difference  was  one  of  age  — 
the  adult  organism  was  more  resistant  by  virtue  of  its 
maturity.  An  anatomical  difference  has  been  sought  in  the 
greater  permeability  of  the  delicate  mucous  membrane  of 
the  infant,  but  this  has  been  disputed  as  an  anatomical  fact, 
and  if  true  is  far  from  an  adequate  explanation.  With  the 
new  view  the  difference  is  one  between  an  acute  infection 
with  massive  dosage  of  an  unprotected  organism  on  the  one 
hand  and  on  the  other  the  progress  of  an  infection  localized 
and  made  chronic  by  an  existing  partial  immunity  of  more 
or  less  long  standing,  the  existence  of  an  immunity  through 
infection  being  necessarily  inferred  to  account  for  the 
marked  benignity  of  the  chronic  as  compared  with  the  acute 
tuberculous  process. 

We  have  seen  that  writers  on  the  epidemiology  of  tuber- 
culosis have  erred  in  the  past  by  drawing  general  conclu- 
sions from  local  observations.  It  may  be  inquired  whether 
in  confining  ourselves  to  the  study  of  tuberculosis  as  it 
manifests  itself  in  the  civilized  communities  of  Europe  and 
America  we  are  not  similarly  in  danger  of  obtaining  a  one- 


28  EPIDEMIOLOGY  OF  TUBERCULOSIS 

sided  view  of  the  disease.  For  recent  observations  in  more 
than  one  field  are  making  it  increasingly  apparent  that  a 
very  high  degree  of  tuberculization  exists  in  the  communi- 
ties of  our  civilization.  The  fact  that  all  of  these  commu- 
nities react  in  about  the  same  way  to  the  infection  of  tuber-* 
culosis  corroborates  this  view.  But  we  can  not  understand 
our  types  of  tuberculosis  until  we  know  all  of  the  other 
types  of  the  disease.  "We  can  not  comprehend  how  a  gen- 
eral tuberculization  influences  the  dissemination  and  pro- 
gress of  tuberculous  disease  until  we  know  how  communi- 
ties and  individuals  fare  who  have  not  had  that  previous 
acquaintance  with  the  tubercle  bacillus.  Ranke1  feels  this 
necessity.  In  discussing  the  different  reaction  to  tubercu- 
lous infection  of  the  infant  and  of  the  civilized  adult  he 
expresses  doubt  as  to  the  influence  of  age  and  says  that  it 
is  unfortunately  impossible  to  determine  the  truth  by  appeal 
to  experience  for  the  reason  that  the  percentage  of  adults 
who  react  to  tuberculin  tests  in  civilized  communities  is  so 
high  that  we  can  not  hope  to  ascertain  whether  the  relative 
resistance  of  the  adult  is  due  to  his  age  or  to  his  previous 
contact  with  the  tubercle  bacillus.  This  is  true  so  far  as 
the  civilized  adult  is  concerned  but  not  for  the  members  of 
some  of  the  savage  races  of  the  tropics  and  other  remote 
parts  of  the  globe  where  the  last  and  vanishing  opportunity 
is  to  be  found  for  determination  of  the  important  question : 
what  is  the  reaction  of  the  uninfected  adult  to  tuberculous 
infection?  We  will  therefore  proceed  to  inquire  how  the 
tuberculosis  situation  in  the  tropics  appears  in  the  light  of 
the  new  facts  as  to  the  infectiousness  of  tuberculosis. 

Climatic  conditions  are  now  no  longer  regarded  as  the 
essential  cause  of  tuberculous  disease.  But  the  tropical 
climate  has  not  lost  the  evil  reputation  which  it  had  ac- 

1  Loc.  cit. 


THE  MODERN  ERA  29 

quired  in  the  days  when  it  was  believed  to  be  chiefly  respon- 
sible. It  is  still  given  a  role  in  the  etiology,  but  now  as  one 
of  the  factors  not  usually  of  lung  disease,  as  in  former 
times,  but  of  that  practically  unknown  condition  of  the 
human  organism  which  permits  tuberculous  infection  to  lay 
hold  upon  it,  which  is  called  predisposition.  Yet  as  before 
there  is  no  agreement  as  to  the  especial  meteorological  con- 
ditions which  are  prejudicial.  The  moist  heat  and  stag- 
nant air  of  the  tropical  seaboard  constitute  the  combina- 
tion of  climatic  influences  which  is  mostly  incriminated. 
But  more  weight  is  now  usually  given  to  bad  hygiene,  im- 
morality, alcohol,  and  complicating  diseases  in  increasing 
the  predisposition  to  tuberculosis. 

Now  all  goes  well  with  expositions  of  this  kind  so  long  as 
tuberculosis  can  be  described  as  a  devastating  disease  and 
the  conditions  as  to  climate,  hygiene,  etc.,  can  be  described 
as  bad.  The  causes  assigned  for  the  prevalence  of  tuber- 
culosis might  not,  it  is  true,  be  the  exact  causes  but  it  could 
not  be  proved  that  they  were  not;  the  assumptions  seemed 
to  be  justified  by  the  observed  facts.  But  in  some  places 
the  hygiene  was  not  really  relatively  bad  or  the  predispos- 
ing causes  did  not  seem  to  lead  to  the  results  demanded  by 
prevailing  theory. 

Le  Moine,  writing  of  the  French  posts  in  Oceania,  says 
that  tuberculosis  is  prevalent  in  these  parts  where  life  out 
of  doors  is  a  necessity,  where  hunger  and  want  are  un- 
known, and  where  all  can  be  cleanly.  But,  he  says,  the 
nightly  gatherings  and  an  animal  carelessness  with  the 
various  excretions  favor  the  dissemination  of  tuberculosis. 
The  progress  of  the  disease  which  is  depopulating  these 
islands  is  to  be  imputed  to  three  causes,  climate,  syphilis 
and  alcoholism.  The  climate  of  the  hot  countries  is  very 
debilitating  for  all  human  races.1 

1Ann.  d'Hyg.   et  de  Med.   Colon.     Vol.   6,   1903,  p.   593. 


30  EPIDEMIOLOGY   OF  TUBERCULOSIS 

Blin,  writing  of  Dahomey,  does  not  allude  to  the  climate 
of  tropical  Africa  but  corroborates  Le  Moine's  views  as  to 
alcoholism  and  syphilis.  He  says :  "  Variola,  which  was 
decimating  the  population,  has  been  checked  by  the  accept- 
ance of  vaccination.  But  tuberculosis,  less  feared  because 
less  tangible,  spares  no  one,  striking  down  all  ages  every- 
where, selecting  first  young  infants,  later  the  adolescents. 
Refractory  to  the  most  elementary  rules  of  hygiene  insuffi- 
ciently clothed,  badly  nourished,  crowded  into  confined  huts 
which  shelter  them  neither  from  the  wind  nor  the  rain, 
breathing  an  air  vitiated  by  crowding,  committing  excesses 
of  all  kinds,  profoundly  alcoholic,  the  greater  part  of  the 
Dahomeyans  are  candidates  of  the  first  order  for  tubercu- 
losis."1 

These  will  suffice  as  examples  of  the  effort  of  tropical 
writers  to  explain  the  incidence  of  tuberculosis  in  terms 
of  predisposition.  Increased  opportunity  for  infection  is 
afforded  no  doubt  by  over-crowding  and  by  frequent  gath- 
erings, but  by  these  authors  it  will  be  noted  the  stress  is 
laid  upon  the  personal  hygiene,  alcoholism  and  other  dis- 
eases, especially  syphilis,  in  accounting  for  the  ravages  of 
tuberculosis  in  the  two  races  that  have  been  most  severely 
afflicted  of  late  years.  Now  if  the  natives  were  once  strong 
and  well  while  living  under  the  same  hygienic  conditions^ 
however  defective  their  hygiene  may  seem  to  us,  it  is  not 
permissible  to  ascribe  to  it  nor  to  the  climate  the  role  of 
creating  a  special  predisposition  to  tuberculosis.  On  this 
point  Mayer  does  not  agree  with  Blin.  He  says  of  the 
African  native  that  he  is  naturally  cleanly,  lives  in  a  well- 
aired  hut  (one  may  remark  here  apropos  of  the  remarks  of 
Blin  that  the  air  can  hardly  be  seriously  vitiated  by  over- 
crowding if  the  "hut  does  not  shelter  from  the  wind!)  and 


'Ann.  d'Hyg.  el  de  M6d.  Colon.     Vol.  0.  1903,  p.  460. 


THE  MODERN  ERA  31 

on  account  of  his  scanty  clothing  is  hardened  against  atmos- 
pheric changes.1  We  know  that  the  Dahomeyans  were 
once  a  race  of  redoubtable  warriors.  As  for  the  south  seas, 
much  has  been  written  of  the  ferocious  cannibals  who  once 
made  forays  upon  one  another,  and  whatever  their  faults 
could  not  be  accused  of  lack  of  vigor.  And  we  shall  see  fur- 
ther on  that  the  Samoan  of  the  present  day  does  not  give 
evidence  of  being  debilitated  by  his  climate.  As  for  the 
role  of  syphilis  and  alcohol  there  are  other  countries  in 
which  these  conditions  seem  to  have  a  less  unfavorable 
effect,  as  for  example  French  India,  where  Gouzien,  as  we 
Bhall  see,  instead  of  giving  reasons  for  the  high  mortality 
from  tuberculosis,  is  unable  to  explain  why  the  death-rate 
from  that  disease  is  so  low  in  view  of  the  bad  hygiene,  poor 
food,  alcoholic  excesses  and  the  prevalence  of  syphilis  and 
various  infectious  diseases. 

To  explain  the  high  mortality  from  tuberculosis  of  the 
African  and  the  Polynesian  some  would  still  claim,  as  did 
Hirsch,  a  racial  predisposition.  Certain  facts  seem  to  bear 
out  this  theory ;  thus  in  British  Guiana  it  is  stated  that  in 
the  negroes  the  course  of  tuberculosis  is  rapid  and  of  the 
type  of  caseous  pneumonia,  while  in  the  East  Indian  coolies 
it  is  slower,  more  catarrhal  and  bronchitic.2  In  Sumatra 
Chinese  laborers  on  plantations  have  a  chronic  pulmonary 
tuberculosis  while  the  Javanese  under  the  same  hygienic 
conditions  suffer  from  a  severe  and  acute  tuberculosis.  But 
there  are  other  facts  that  show  that  race  does  not  account 
for  the  observed  differences.  The  Javanese  country  dweller 
is  helpless  before  tuberculous  infection,  it  is  true,  but  the 
city  dwellers  of  the  same  race  are  beginning  to  show  a  well 

1  Fortbldgskurse  d.  Allgemeines  Krankenhauses,  Hamburg-Eppendorf. 
Vol.  12,  1911,  p.  23. 

-  Endemic  Diseases  in  British  Guiana  and  on  Certain  Racial  Suscepti- 
bilities.    Robert  Grieve,  British  Med.  Jour.    Vol.  1,  1890,  p.  468. 


32  EPIDEMIOLOGY   OF  TUBERCULOSIS 

marked  resistance.  It  is  reported  from  German  Samoa 
that  natives  imported  from  other  islands  are  ravaged  by 
tuberculosis,  sixty  per  cent,  of  the  deaths  among  them  in 
1909  being  from  that  cause,  but  that  the  native  population 
of  Samoa,  while  they  have  a  high  morbidity  rate  from 
tuberculosis,  have  a  very  low  rate  of  mortality.1  But  the 
Maoris  of  New  Zealand,  who  have  narrowly  escaped  exter- 
mination from  various  causes  of  which  tuberculosis  is  one, 
belong  to  the  same  race  as  the  Samoans.  The  West  Indian 
colored  regiment  of  tne  British  Army  has  a  higher  rate  for 
tuberculosis  than  the  white  troops  in  the  West  Indies  but 
when  this  regiment  is  stationed  in  Sierra  Leone  its  rate 
of  incidence  of  tuberculosis  is  much  higher  than  that  of  the 
native  Sierre  Leone  regiment  under  the  same  conditions.2 
Evidently  something  besides  racial  peculiarities  (in  this 
case  probably  uncinariasis  acquired  in  Jamaica  where  a 
large  percentage  of  the  population  harbor  the  hook-worm) 
accounts  for  the  fact  that  the  regiment  always  has  more 
tuberculosis  than  other  troops  with  which  it  may  be  serv- 
ing. 

We  may  say  that  comparing  with  one  another  the  utter- 
ances of  the  writers  on  tropical  tuberculosis  it  appears  that 
neither  geographical  position,  climate,  sanitation  nor  race 
account  for  the  observed  differences  in  the  incidence  and 
clinical  course  of  tuberculosis  in  the  tropics,  and  that  pre- 
disposition is  as  unsatisfactory  an  explanation  for  suscepti- 
bility to  tuberculous  infection  as  it  has  proved  in  the  tem- 
perate zones.  Indeed  it  is  more  unsatisfactory.  In  many 
tropical  communities  the  tuberculosis  situation  is  practi- 
cally the  same  as  in  the  northern  civilization  but  what  shall 
be  thought  of  predisposition  when  the  incidence  of  tubercu- 

1  Heim,  Zeitschrift  fur  Tuberkulose.    Vol.  20,  1913,  p.  313. 

2  Tuberculosis  among  Civilized  Africans.  F.  Smith,  Jour,  of  Trop.  Med 
Vol.  8,  1905,  p.  19. 


THE   MODERN   ERA  33 

losis  is  seen  to  be  directly  as  the  exposure  to  it  and  healthy 
and  vigorous  men  are  stricken  down  with  an  acutely  fatal 
form  of  the  disease?  Much  of  the  confusion  of  apparently 
contradictory  facts  is  to  be  explained  by  the  existence  of 
different  types  of  tuberculosis. 


CHAPTER  III 
TUBERCTJLIZED  RACES 

So  far  as  the  types  of  tuberculosis  are  concerned  tropical 
countries  may  in  a  general  way  be  divided  into  two  classes. 
In  the  first  tuberculosis  is  a  prevalent  disease,  as  it  is  with 
us,  the  morbidity  is  high,  the  mortality  from  tuberculosis 
is  as  a  rule  higher  than  the  average  of  more  civilized  coun- 
tries, as  would  be  expected  in  populations  for  the  most  part 
poor  and  ignorant.  The  death-rate  from  tuberculosis  bears 
a  certain  relation  with  the  general  death-rate,  both  dimin- 
ishing when  sanitation  is  improved.  Chronic  pulmonary 
tuberculosis  is  the  common  form  of  the  disease.  It  is  re- 
garded as  more  or  less  curable,  at  all  events  may  pursue  an 
extremely  chronic  course.  Tuberculosis  of  bones,  joints 
and  glands  is  more  or  less  frequently  met  with.  The  popu- 
lation is  generally  increasing  or  at  least  there  is  no  fear  of 
depopulation. 

In  the  second  class  tuberculosis  is  a  comparatively  rare 
disease,  the  morbidity  rates  are  low,  the  mortality  of  those 
that  fall  sick  is  frightfully  high.  Pulmonary  tuberculosis 
in  its  chronic  types  is  rare  or  unknown.  Tuberculosis  pre- 
vails as  an  acute  and  rapidly  fatal  general  infectious  dis- 
ease. It  may  spread  like  an  epidemic.  The  population 
diminishes  and  depopulation  may  be  feared. 

Examples  of  the  first  class  are  the  tropical  portions  of 
the  continent  of  Asia,  the  Philippines,  Samoa  and  Hawaii. 
Tropical  Africa  and  the  greater  number  of  the  islands  of 
the  Pacific  belong  to  the  second. 

The  difference  between  the  two  classes  that  at  once  at- 
tracts attention  is  that  the  countries  of  the  first  class  have 

34 


TUBERCULIZED  RACES  35 

long  been  more  or  less  civilized  or  have  been  long  in  contact 
with  civilized  or  semicivilized  races  and  have  therefore  been 
exposed  to  infection  with  tuberculosis,  while  those  of  the 
second  class  contain  peoples  who  by  reason  of  their  inac- 
cessibility in  the  interior  of  vast  continents  or  on  remote 
islands  of  the  Pacific  have  had  little  or  no  contact  with 
civilization  until  very  recent  times.  There  are  some  coun- 
tries which  might  be  assigned  to  either  group,  namely  those 
in  which  the  seacoast  and  especially  the  seacoast  cities  have 
long  been  infected  with  tuberculosis  while  the  interior  of 
the  country  is  practically  free  of  it.  An  example  appears 
to  be  Java.  There  are  also  many  other  countries  as  India 
and  the  Philippines  where  the  population  is  composed  of 
many  different  peoples  in  which  the  amount  of  contact  with 
civilization  and  therefore  probably  to  some  extent  the  de- 
gree of  tuberculization  differ  widely.  The  above  classifica- 
tion is  therefore  only  true  in  a  general  way,  but  it  serves 
to  call  attention  to  a  very  significant  distinction. 

In  view  of  the  importance  of  a  clear  understanding  of 
this  matter  it  may  be  well  to  consider  more  in  detail  the 
facts  regarding  the  character  of  tuberculosis  as  manifested 
on  the  one  hand  in  races  long  in  touch  with  civilization  and 
on  the  other  hand  in  the  races  nearly  "  virgin  "  so  far  as 
tuberculosis  is  concerned. 

First,  as  to  the  old  countries.  In  China  the  conditions 
under  which  the  inhabitants  of  towns  live  would  seem  to 
the  sanitarian  preeminently  calculated  to  result  in  a  heavy 
mortality  from  tuberculosis.  The  population  is  densely 
aggregated.  The  houses  are  small  and  low,  built  closely 
together,  badly  ventilated  and  badly  heated.  The  streets 
are  narrow  and  crooked  and,  as  if  to  ensure  against  free 
air  and  sunshine,  it  is  frequently  the  practice  to  stretch 
an  awning  over  them.     The  water-supply  is  badly  polluted, 


36  EPIDEMIOLOGY   OF  TUBERCULOSIS 

the  disposal  of  faecal  matter  is  so  incredibly  bad  that  the 
stenches  are  sometimes  insupportable  to  the  uninitiated. 
The  majority  of  the  people  are  underfed  according  to  our 
ideas  and  what  food  they  have  is  almost  entirely  vegetable. 
Yet  they  seem  somehow  to  have  established  a  modus 
vivendi  so  far  as  thoracic  disease  is  concerned,  for,  accord- 
ing to  Dudgeon  of  Pekin,  diseases  of  the  chest  on  the  whole 
are  remarkably  rare  in  China.1  Pleurisy,  pneumonia  and 
acute  bronchitis  are  hardly  known  and  phthisis  is  far  from 
being  as  common  as  in  this  country.  He  reports  Dr.  Wang 
as  saying  that  phthisis  is  tolerably  prevalent  in  Canton  but 
is  by  no  means  so  common  as  in  Europe  and  Amer- 
ica.2 It  is  difficult  to  say  why  this  should  be  the 
case,  since  the  causes  which  produce  consumption, 
such  as  bad  air,  insufficient  food  and  exercise,  bad 
hygiene,  etc.,  must  be  much  more  operative  here  than 
in  the  more  civilized  countries  of  Europe  and  Amer- 
ica. The  Chinese  of  Canton,  according  to  Dr.  Wang, 
are  not  liable  to  acute  affections  of  the  chest.  He  saw  only 
one  case  of  acute  bronchitis  in  three  years.  Idiopathic 
pleurisy  and  pneumonia  he  had  never  seen,  but  chronic 
bronchitis  is  common.  In  Shanghai,  according  to  Dudgeon, 
chest  affections  are  not  generally  severe.  At  Hankow,  it 
is  reported  by  one  physician  that  consumption  is  compara- 
tively infrequent,  which  may  be  due,  he  says,  to  the  great 
frequency  of  chronic  bronchitis.  Another  physician  says 
of  Hankow  that  more  than  one-half  of  the  people  of  the 
town  are  debarred  from  exercise  and  rarely,  if  ever,  inhale 
fresh  air,  the  subsoil  is  saturated  with  water,  hemoptysis 

'Glasgow  Med.  Jour.     Vol.  9,  1877,  p.  322. 

1 "  Diseases  of  the  viscera  of  an  acute  inflammatory  nature  are  not  so 
fatal  or  rapid  among  the  Chinese  as  Europeans,  nor  do  consumptions  carry 
ofr  ho  large  a  proportion  of  the  inhabitants  as  in  the  United  States."  The 
Middle  Kingdom,  p.   189    (S.   Wells  Williams). 


TUBERCULIZED  RACES  37 

is  of  frequent  occurrence.  The  same  authority  expresses 
his  surprise  at  the  small  amount  of  tuberculosis  among 
the  country  people  who  live  on  insufficient  vegetable  food. 
Tt  will  at  once  occur  to  the  reader  that  the  chronic  bron- 
chitis which  is  reported  to  be  so  frequent  may  be  in  part 
at  least  a  chronic  pulmonary  tuberculosis.  This  possibility 
is  however  considered  and  dismissed  by  the  reporters. 
Whatever  the  facts  may  be  with  regard  to  this,  there  would 
seem  to  be  at  least  no  doubt  that  the  tuberculosis  that  is 
present  in  China  is  preponderatingly  chronic  and  benign. 
On  the  other  hand,  according  to  McDill,1  it  is  recently  re- 
ported from  Soochow,  Ping  Yin  and  Wenchow  that  tuber- 
culosis is  the  most  common  of  all  diseases  and  the  curse  of 
the  country;  there  is  no  form  but  what  is  met  with. 
Patients  respond  well  to  modern  treatment.  These  last 
reports  are  made  by  surgeons  who  would  naturally  see  the 
surgical  forms  of  tuberculosis  with  especial  frequency. 
Their  remarks  indicate  a  thoroughly  tuberculized  popula- 
tion, in  which  the  course  of  the  disease  might  be  expected 
to  be  benign,  to  "  respond  well  to  treatment,"  in  the  large 
majority  of  cases. 

Hong  Kong,  Shanghai  and  perhaps  Hankow  are  the  only 
Chinese  cities  in  which  statistics  of  any  accuracy  are  kept. 
Dold2  reports  as  to  the  tuberculosis  mortality  of  the  Inter- 
national Settlements  of  Shanghai  from  figures  furnished  by 
the  Health  Office.  The  average  mortality  from  all  causes 
from  1902  to  1914  inclusive,  was  foreigners  17.4,  Chinese 
18.2  per  1000.  The  percentage  of  deaths  from  tuberculosis 
in  the  total  mortality  was :  foreigners  12.53,  Chinese  16.72. 
The  average  ratio  of  deaths  from  tuberculosis  per  1000  of 
population  was:  foreigners  2.2,  Chinese  2.7.     The  conclu- 

1  Tropical  Surgery  and  Diseases  of  the  Far  East.     1918. 
'Deutsche  Med.  Wochenschr,  1915,  p.  1038. 


38  EPIDEMIOLOGY    OF   TUBERCULOSIS 

sions  which  Dold  draws  from  these  figures  are  that  while 
bad  hygienic  conditions  in  the  native  population  account  for 
the  excess  of  mortality,  the  Chinese  must  be  considered  to 
be  at  least  as  susceptible  to  tuberculosis  as  the  peoples  of 
Europe  and  America.  Among  the  foreigners  are  of  course 
comprised  many  Europeans  of  the  mercantile  class,  mostly 
males  of  the  early  and  middle  periods  of  adult  life,  living 
under  comparatively  comfortable  conditions,  who  are  here 
compared  with  half  a  million  natives  of  all  ages  and  both 
sexes  most  of  whom  are  very  poor  and  all  of  whom  live 
under  bad  hygienic  conditions  from  our  point  of  view.  But 
in  the  foreign  population  are  no  doubt  included  many  Eura- 
sians who  live  more  unhygienically  than  the  Chinese  and 
are  very  subject  to  phthisis.1  It  may  be  granted  that  the 
statistics  for  the  Chinese  are  not  as  accurate  as  those  of  the 
foreigners.  But  no  allowance  is  made  for  the  repatriation 
of  the  European  tuberculous.  It  may  be  reasonably  as- 
sumed that  a  considerable  percentage  of  the  foreigners  will 
return  to  their  native  lands  when  afflicted  with  tuberculosis, 
so  that  the  mortality  rate  does  not  furnish  a  true  picture 
of  the  tuberculosis  situation  of  this  class.  On  the  other 
hand,  the  Chinese  of  Shanghai  who  come  from  the  country 
are  sure  to  return  to  their  native  villages  when  they  learn 
that  they  have  consumption.1  It  is  difficult  to  determine 
what  the  real  facts  are,  but  we  may  perhaps  be  justified  in 
saying  that  the  Chinese  have  at  least  as  much  resistance  to 
tuberculosis  as  Europeans  would  have  if  compelled  to  live 
under  the  same  conditions  of  hygiene. 

According  to  Paige"  tuberculosis  is  widespread  in  all  of 
South  China  but  in  Shantung  is  rarer  than  in  Europe.  In 
Chung  King,  Almy3  states,  tuberculosis  of  the  lungs  has  a 

'Dr.  Andrew  H.   Woods,  formerly  of  Canton.     Personal  communication. 
•-  Arch.  f.  SchifFs-tL  Tropenhyg.     Vol.   16.  1912,  p.  6. 
*  Klin.  Jahrbuch  Vol.  20,  p.  403. 


TUBERCULIZED  RACES  39 

preponderatingly  chronic  course.  Missionaries  report  that 
not  rarely  the  young  Chinese  have  attacks  of  hemoptysis, 
from  which  they  recover  completely.  (The  apparent  in- 
nocuousness  of  hemoptysis  among  the  Chinese  is  reported 
from  Hankow  also.)  Cases  are  known  in  which  European 
physicians  have  predicted  speedy  death  in  which  the  pa- 
tients lived  for  years,  and  some  even  appeared  to  get  well 
This  in  a  country  of  cold  wet  winds  and  constant  fog,  the 
sun  shining  so  rarely  that  it  is  popularly  believed  that  the 
dogs  bark  at  it  when  it  does  appear!  Gland  and  bone 
tuberculosis  are  common  forms.  Large  joints  are  fre- 
quently tuberculous. 

In  Cochin-China,  Henaff  reports  that  tuberculosis  has 
always  existed  and  seems  to  be  disseminated  even  in  the 
remotest  parts.1  The  evolution  of  tuberculosis  is  slow  and 
torpid,  some  patients  reaching  an  advanced  age.  One 
rarely  sees  acute  tuberculosis.  There  are  no  statistics 
which  are  reliable,  but  Henaff  says  that  tuberculosis  must 
be  common  in  a  population  so  wretchedly  poor  and  so  care- 
less of  hygiene.  Mothers  have  the  habit  of  chewing  the 
food  before  feeding  it  to  their  young  children  and  if  tuber- 
culous must  often  communicate  the  disease  in  that  way. 

Gouzien2  states  with  reference  to  French  India  that  it  is 
impossible  to  obtain  statistics  because  records  of  death  are 
kept  only  by  the  police,  but  goes  on  to  say  that  the  low 
mortality  from  tuberculosis  is  surprising  in  view  of  the 
wretched  huts  in  which  the  greater  part  of  the  inhabitants 
live,  their  poor  food,  uncleanness,  alcoholic  excesses  and  the 
prevalence  of  syphilis  and  various  other  infectious  diseases, 

In  Tonkin,  according  to  Gaide,3  the  Annamites  believe 
that  tuberculosis  has  always  existed  and  that  pulmonary 

1  Ann.  d'Hyg.  et  de  Med.  Colon.     Vol.  6,  1903,  p.  50. 
aIdem.     Vol.   7,   1904,  p.  543. 
•  Idem.     Vol.  8,  1905,  p.  112. 


40  EPIDEMIOLOGY   OF  TUBERCULOSIS 

tuberculosis  does  not  develop  until  the  thirtieth  year  of 
life.  Tuberculosis  of  bones,  joints  and  glands  is  frequent. 
According  to  Wilkinson,  statistics  seem  to  show  that 
tuberculosis  is  increasing  in  India.1  It  is  doubtful  however 
whether  the  increase  is  real  or  apparent,  in  the  latter  case 
being  due  to  more  accurate  diagnosis  and  registration. 
Deaths  in  native  villages  are  registered  by  uneducated 
watchmen,  hence  the  statistics  are  unreliable.  In  the  great 
cities  however  deaths  have  been  reported  by  physicians  for 
some  years.  In  Madras  the  ratio  per  1000  has  fallen  from 
1.6  in  1905  to  0.4  in  1910.  The  early  ratios  of  Bombay 
were  high.  The  death-rate,  3.64  per  1000  in  1906,  declined 
to  2.12  in  1911.  In  Calcutta  the  rate  was  1.2  in  1901,  2.6 
in  1907  and  2.3  in  1909,  1910  and  1911.  Judging  by  the 
ratio  of  tuberculosis  to  other  diseases  treated  in  hospitals 
and  dispensaries,  it  would  appear  that  tuberculosis  is  on  the 
increase.  Bombay  has  been  the  worst  infected  city  for 
many  years  and  its  Presidency  the  most  infected  province. 
The  increase  of  industrialism  has  led  to  emigration  from 
the  country  into  towns,  which  has  resulted  in  great  over- 
crowding of  city  tenements.  Seventy-six  per  cent,  of  the 
Bombay  population  live  in  one-room  tenements  with  narrow 
passages  but  two  feet  wide  between  six-story  buildings. 
Similar  conditions  prevail  to  some  extent  in  other  large 
towns.  Muthu2  states  that  he  was  pleased  to  find  many 
cases  of  healed  tuberculosis  in  places  like  Nepal  where, 
though  the  sanitation  is  primitive,  life  is  not  strenuous, 
which  confirms  his  experience  in  England  that  want  and 
anxiety  more  than  insanitation  renders  the  human  organ- 
ism susceptible  to  this  disease.  The  admission-rate  for  pul- 
monary tuberculosis  for  the  Bengal  army  (European)  ac- 
cording to  Macpherson2  in  1870-1879  was  8.3  per  1000,  in 

1  Proc.  Royal  Soc.  of  Med.     Vol.  7,  Pt.  2,  1913-1914,  p.  195. 

2  The  Practitioner.     Vol.  94,  1915,  p.  872. 


TUBERCULIZED  RACES  41 

1879-1884  was  7  for  all  tuberculosis,  in  1886-1890  for 
European  troops  in  India  was  3.5  for  all  tuberculosis;  in 
1907-1911  it  was  1.60,  in  1912  1.20  per  1000.  The  figures 
for  both  European  and  native  troops  show  a  rise  according 
to  Wilkinson,  then  a  decline  which  is  due  to  the  providing 
of  better  barrack-accommodations.  But  Johnston1  states 
that  while  the  tuberculosis  in  the  British  army  as  shown  by 
the  admission-rate  has  decreased  greatly  since  1885,  in  the 
Indian  army  the  rate  has  increased  from  an  originally  low 
level,  the  difference  being  due  to  better  diagnosis  of  late 
years  and  to  the  presence  of  more  Gurkhas  who  are  very 
susceptible  to  tuberculosis.  The  barracks  have  been  much 
improved  of  late  years  but  those  of  the  British  army  more 
than  those  of  the  Indian  army.  Pulmonary  tuberculosis  is 
practically  the  only  form  of  tuberculosis  in  the  Indian  army. 

In  Smyrna,  Barret2  says,  phthisis  is  rare  and  of  slow 
course,  but  scrofula  is  very  common  in  the  poorer  classes. 

In  the  old  French  colony  of  Martinique,  Lidin3  states, 
pulmonary  tuberculosis  is  the  most  common  chronic  dis- 
ease except  diarrhoea,  but  seems  to  follow  the  same  evolu- 
tion as  at  Paris.  It  generally  pursues  a  slow  and  torpid 
course.  Bone  and  joint  tuberculosis  is  very  rare.  He 
quotes  St.  Vel,  who  thinks  that  the  influence  of  hot  climates 
is  to  tuberculize  only  the  lungs,  and  states  that  an  old 
physician  is  of  the  opinion  that  in  spite  of  the  great  humid- 
ity tuberculosis  is  less  prevalent  in  Martinique  than  in 
France.  But  in  1840,  according  to  Hirsch,4  Levacher  re- 
ported that  pulmonary  tuberculosis  developed  in  the  An- 
tilles is  promptly  fatal,  passing  through  its  stages  more 
rapidly  than  in  Europe. 

'Brit.  Jour,  of  Tub.     Vol.  2,  1908,  p.  20. 
2  Arch,  de  Med.  Naval.    Vol.  30,  1878,  p.  81. 
8  Ann.  d'Hyg.  et  Med.  Colon.    Vol.  7,  1904,  p.  84. 
*Loe.  cit. 


42  EPIDEMIOLOGY  OF  TUBERCULOSIS 

In  the  French  colony  of  Reunion,  the  island  was  origi- 
nally populated  by  a  mixed  class  of  Malays  and  Africans  who 
brought  tuberculosis  with  them.  According  to  Calmette,1 
tuberculous  infection  is  as  common  there  as  in  the  large 
French  industrial  cities,  occurring  mostly  as  pulmonary 
tuberculosis.  Bovine  tuberculosis  is  said  to  be  present  — 
an  unusual  occurrence  in  the  tropics  —  about  thirty  per 
cent  of  the  milk  used  being  infected. 

In  the  Philippines  tuberculosis  is  very  prevalent.  It  is 
the  opinion  of  American  army  surgeons  who  have  consid- 
ered the  reasons  for  the  high  incidence  of  tuberculosis  that 
the  health  of  the  Filipinos  is  impaired  especially  by  infec- 
tion with  malaria  and  uncinariasis.2  Improvement  in  the 
death-rate  from  tuberculosis  as  well  as  in  the  general  death- 
rate  has  been  effected  by  measures  of  general  sanitation 
and  also  by  treatment  for  intestinal  parasites.3  At  Bilibid 
prison  there  was  an  uninterrupted  increase  in  the  death- 
rate  among  the  prisoners  from  1902  to  1905,  the  mortality 
becoming  more  than  200  per  1000  per  annum.  In  1904 
more  than  50  per  cent,  of  the  deaths  were  due  to  tubercu- 
losis. Sanitary  improvements  reduced  the  mortality  to 
about  75  per  1000.  The  sufferers  from  tuberculosis  were 
in  part  isolated.  Examination  of  the  stools  showed  that 
84  per  cent,  of  the  prisoners  were  infected  with  intestinal 
parasites,  60  per  cent,  having  hookworm.  Under  treatment 
appropriate  for  this  condition  the  death-rate  fell  to  less  than 
20  per  1000.  Deaths  from  tuberculosis  at  Bilibid  were  in 
1904,  161;  in  1905,  179;  in  1906,  51;  in  1907,  35.  In 
1914  the  report  is  that  the  deaths  at  Bilibid  from  pulmo- 
nary tuberculosis  numbered  55,  in  1915  all  deaths  from 

1  Ann.  de  l'lnstitut  Pasteur,  Vol.  26,  1912,  p.  497. 

*W.  P.  Chamberlain,  Am.  Jour.  Trop.  Dis.  and  prev.  Med.     Vol.  1,  1913- 
1914,  p.  12. 

1  Victor  G.  Heiser,  Med.  Ree.  Dec.  12,  1908,  p.  1006. 


TUBERCULIZED  RACES  43 

tuberculosis  were  53  or  9.65  per  1000.  In  1916  the  Direc- 
tor of  Health  gives  the  number  of  deaths  from  tuberculosis 
as  33,  which  he  states  to  be  at  the  rate  of  3.87  per  1000. 
This  very  gratifying  result  is  a  striking  example  of  the 
benefit  which  may  be  derived  from  improvement  of  the 
general  health  in  diminishing  the  mortality  from  tuberculo- 
sis in  a  special  class  of  individuals  coming  from  a  commu- 
nity which  is  thoroughly  infected.  Manila  has  long  been 
in  contact  with  the  outside  world  and  this  fact  is  shown  by 
the  type  of  pulmonary  tuberculosis  which  prevails.  Ac- 
cording to  Musgrave1  its  course  is  exceedingly  chronic, 
"  more  so  perhaps  than  that  encountered  in  temperate  cli- 
mates." 

Table  No.  1  has  been  compiled  from  the  annual  reports 
of  the  Director  of  Health. 

In  this  table  no  allowance  is  made  for  increase  of  popula- 
tion between  the  censuses.  Hence  in  the  later  years  (for 
example  1911-12  and  1916)  of  a  period  during  which  a  con- 
stant population  is  assumed  the  ratios  per  1000  living  are 
somewhat  higher  than  they  should  be.  The  general  mor- 
tality rate  and  the  death  rates  for  tuberculosis  are  high 
compared  with  the  corresponding  rates  of  the  temperate 
zone.  According  to  Brewer2  in  1908  there  were  10,646 
deaths  from  all  causes  at  Manila.  Of  these  1240  or  11.07 
per  cent,  were  due  to  tuberculosis,  a  rate  of  5.54  per  1000 
living.  The  mortality  rate  of  the  United  States  registra- 
tion area  in  1910  was  15  per  1000  living,  that  of  England 
and  Wales  13.5,  that  of  Germany  16.2.  The  death-rate 
from  pulmonary  tuberculosis  in  Manila  in  1908  was  4.86 
per  1000,  that  of  five  American  cities  of  approximately  the 

1  Phil.  Jour,  of  Sci.  B.  Vol.  5,  1910,  p.  313. 

2  Ibid.,  p.  331. 


44 


EPIDEMIOLOGY   OF  TUBERCULOSIS 


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TUBERCULIZED  RACES  45 

same  population  was:  Indianapolis  1.85,  Louisville  1.84, 
Providence  1.53,  St.  Paul  .88. 

There  appears  to  be  an  improvement  in  the  general  mor- 
tality rates  of  the  later  years  of  this  table  and  a  slight  im- 
provement in  the  death-rate  from  tuberculosis.  On  the 
other  hand  the  percentage  of  deaths  from  pulmonary  tuber- 
culosis in  the  general  mortality  (which  of  course  is  not 
affected  by  the  failure  to  allow  for  increase  of  population) 
shows  a  distinct  increase.  A  diminution  in  the  general 
mortality  is  effected  mainly  by  the  suppression  of  acute 
infectious  diseases,  the  result  of  which  is  that  some  who 
would  have  been  carried  off  by  one  of  these  diseases  live  on 
to  die  of  tuberculosis  at  a  later  time.  As  the  saying  is: 
"  Not  every  one  survives  long  enough  to  die  of  his  tubercu- 
losis." The  table  is  typical  of  a  well-tuberculized  com- 
munity with  a  fairly  constant  death-rate  from  tuberculosis, 
in  which  the  hygiene  is  bad.  Evidently  much  remains  to 
be  done  in  the  way  of  education  and  sanitation. 

In  Brazil  according  to  Ferreira1  tuberculosis  was  more 
rife  in  the  early  history  of  the  country  than  it  is  at  present. 
In  1847  it  caused  one-third  of  the  deaths  at  Rio  de  Janeiro. 
The  ratio  of  deaths  from  tuberculosis  per  10,000  population 
in  1860  was  122.1,  in  1908  it  was  41.5.  Tuberculosis,  he 
says,  was  particularly  grave  at  first  on  account  of  the  ab- 
sence of  immunity  which  at  length  develops.  But  improve- 
ment in  sanitation  has  much  to  do  with  the  diminished 
mortality  from  tuberculosis.  For  example  in  Recife  the 
capital  of  Pernambuco,  an  old  town  where  hygiene  is  de- 
fective, the  rate  is  73  per  10,000  while  two  other  towns, 
Manaus  and  Belem,  in  spite  of  their  very  hot  climate,  being 
newly  built  and  with  straight  and  clean  streets,  have  a  mor- 
tality of  21.3  and  22  per  10,000  respectively,  and  this  inde- 

tuberculosis.     Vol.  14,  1915,  p.  15. 


46  EPIDEMIOLOGY  OF  TUBERCULOSIS 

pendently  of  measures  directed  specifically  against  bacillary 
infection. 

The  island  of  New  Caledonia  in  the  Pacific  was  selected 
as  a  penal  settlement  by  the  French  on  account  of  its  sup- 
posed salubrity  and  its  excellent  climate,  Cayenne  in  South 
America,  which  was  used  for  the  same  purpose,  having 
proved  extremely  unhealthful.  The  first  convoys  were 
diverted  from  Cayenne  to  New  Caledonia  on  account  of  an 
epidemic  of  yellow  fever  at  the  former  place.  There  were 
5187  deaths  among  the  convicts  at  Cayenne  in  the  period 
from  1868  to  1886  inclusive  in  a  mean  annual  strength  of 
approximately  3800.  Of  these  deaths  472.9  per  1000  deaths 
were  due  to  malaria,  81.3  per  1000  to  diarrhoea  and  dysen- 
tery, 62.42  per  1000  to  tuberculosis,  27.5  per  1000  to 
typhoid  fever. 

There  is  no  malaria  in  New  Caledonia.  This  having  been 
the  chief  cause  of  death  at  Cayenne,  the  statistics  of  gen- 
eral mortality  at  New  Caledonia  give  a  ratio  per  1000  often 
less  than  one-half  that  of  Cayenne.  But  aside  from  mala- 
ria the  results  of  the  change  were  disappointing.  At  New 
Caledonia  the  deaths  from  diarrhoea  and  dysentery  were 
277.6  per  1000  deaths,  from  tuberculosis  110  per  1000,  from 
typhoid  fever  107.8  per  1000,  from  anemia  56.5  per  1000. 
Especial  disappointment  was  felt  as  respects  the  tuberculo- 
sis mortality.  While  for  the  whole  period  the  ratios  were 
as  has  been  stated  62.42  per  1000  in  Guiana  and  110  in  New 
Caledonia,  in  the  latter  part  of  the  period  the  ratios  of  New 
Caledonia  showed  an  even  greater  increase.  Thus,  for 
example,  the  annual  ratios  of  deaths  from  tuberculosis  per 
1000  deaths  for  the  five  years  from  1881  to  1885  inclusive 
were  226,  202,  154,  122  and  93  in  New  Caledonia;  27,  74, 
38,  46.9  and  27  in  Cayenne.  With  the  idea  in  part  of 
diminishing  the  death-rate  from  tuberculosis  the  French 


TUBERCULIZED  RACES  47 

Government,  instead  of  sending  its  convicts  to  the  pestilen- 
tial swamps  of  French  Guiana,  transports  them  to  an  island 
where  the  mild  climate  invites  life  in  the  open  air  and 
where  the  European  is  able  to  engage  in  manual  labor  with- 
out injury,  and  the  result  is  a  great  increase  in  tuberculosis 
mortality!  This  fact,  says  the  reporter  Kermorgant.1  has 
never  received  an  explanation.  Here  is  an  interesting 
problem  in  tropical  sanitation  which  will  repay  study.  The 
explanation  can  not  be  altogether  bad  hygienic  conditions 
for  Kermorgant  expressly  states  that  the  prisoners  at  New 
Caledonia  were  not  overworked,  spent  the  day  in  the  open 
air  and  passed  the  night  in  well  aired  barracks  in  a  health- 
ful and  not  too  warm  climate.  But  from  the  standpoint 
of  modern  sanitation  it  is  evident  from  the  large  number 
of  deaths  which  are  due  to  diarrhoea,  dysentery  and  typhoid 
fever  in  both  colonies  that  the  water-supply  was  infected  in 
both,  but  was  considerably  worse  at  New  Caledonia.  Now 
in  a  thoroughly  tuberculized  population  in  the  absence  of 
epidemic  disease  the  mortality  from  tuberculosis  rises  and 
falls  with  the  general  mortality  and  especially  with  th£ 
mortality  from  typhoid  fever  and  other  water-borne  dis- 
eases. We  have  therefore  a  higher  mortality  from  tuber- 
culosis at  New  Caledonia  than  at  Cayenne  because  the  water 
supply  was  more  seriously  infected.  Furthermore  the  oc- 
currence of  anemia  as  a  prominent  cause  of  death  suggests 
the  probability  of  the  presence  of  uncinariasis  as  a  debili- 
tating factor  which  might  seriously  favor  the  incidence  of 
tuberculosis  (uncinariasis  has  been  reported  from  New 
Caledonia.  Sprue  which  might  also  be  considered  as  a 
cause  of  the  anemia  is,  however,  said  not  to  prevail  there).2 
That  the  convicts  from  France  had  come  into  previous  con- 

1  Ann.  d'Hyg.  et  Med.  Colon.     Vol.  6,  1903..  p.  153. 
2 Colonel  Ashford.     Personal  communication. 


48  EPIDEMIOLOGY   OF  TUBERCULOSIS 

tact  with  tuberculosis  may  be  assumed.  Whether  this  is 
true  to  the  same  degree  of  all  the  elements  that  go  to  make 
up  the  cosmopolitan  population  of  the  penal  colony  is  of 
course  not  so  certain.  The  Arabs  had  a  death-rate  higher 
than  the  average  at  Cayenne,  83  per  1000,  which  increased 
to  114.5  at  New  Caledonia,  a  smaller  increase  than  ob- 
tained in  other  groups,  showing  that  the  development  of  the 
tuberculosis  was  less  influenced  by  changes  in  the  hygienic 
conditions.  It  is  therefore  quite  possible  that  there  were 
among  them  some  individuals  who  had  not  had  the  full 
measure  of  protection  against  tuberculosis  which  civiliza- 
tion seems  to  confer.  But  that  the  convicts  on  the  whole 
were  thoroughly  tuberculized  is  shown  by  comparison  of 
their  mortality  with  that  of  the  prison  guards.  These 
guards  were  French  soldiers,  largely  non-commissioned  offi- 
cers, picked  men  of  long  service,  who  had  undoubtedly  long 
been  in  contact  with  the  diseases  of  civilization.  In  Guiana 
among  this  class  the  ratio  of  mortality  from  tuberculosis 
was  145.4  per  1000  deaths  but  in  New  Caledonia  it  was  228, 
a  considerably  higher  mortality  even  than  that  of  Arab  con- 
victs. Presumably  the  hygiene  of  the  guards  was  at  least 
as  good  as  that  of  their  charges.  We  must  ascribe  the  high 
mortality  in  both  classes,  guards  and  convicts,  to  the  same 
causes,  in  all  probability  causes  of  an  infectious  nature 
which  prepare  the  soil  for  tuberculosis.  Calmette1  says  of 
the  native  population  of  New  Caledonia  that  tuberculous 
infection  extends  with  terrifying  intensity.  The  question 
that  at  once  arises  in  this  connection  is  whether  or  not  the 
tuberculosis  was  of  recent  introduction  among  the  natives, 
or  whether,  as  among  the  whites,  the  special  fatality  of 
the  disease  is  due  to  less  obvious  causes  than  primary  infec- 
tion of  the  race.     Naturally  the  native  would  have  practi- 

1  Loc.  cit. 


TUBERCULIZED  RACES  49 

cally  the  same  water-supply  as  the  convicts  and  would  be 
exposed  to  infection  from  the  prevailing  diseases  perhaps 
even  to  a  greater  extent  than  the  former.  It  is  improbable 
in  view  of  the  long  period  during  which  the  natives  have 
been  in  contact  with  the  whites  that  we  have  here  a  tuber- 
culosis of  a  virgin  race,  however  severe  the  ravages  of  the 
disease,  and  we  are  confirmed  in  this  view  by  Mesnard,1 
who  states  that  de  Rochas  wrote  as  early  as  1862  that  pul- 
monary tuberculosis  was  the  scourge  of  the  native  popula- 
tion of  New  Caledonia.  Tuberculosis  is  therefore  no  new 
disease.  Furthermore  Mesnard  says  that  the  symptoms 
which  most  attracts  the  attention  of  the  natives  is  the 
emaciation  of  the  consumptive.  It  seems,  Mesnard  goes  on 
to  say,  that  among  the  Kanakas  tuberculosis  has  a  tendency 
to  evolve  rapidly  and  to  terminate  in  an  atonic  and  torpid 
fashion  as  pulmonary  phthisis.  Other  manifestations  of 
tuberculosis  are  rarely  seen.  And  Boyer  remarks:  the 
Kanaka  is  scrofulous  from  infancy;  tuberculosis  does  not 
lay  hold  of  him  until  he  approaches  his  twentieth  year.2 
Hence  we  conclude  that  not  only  in  the  penal  settlements, 
but  also  among  the  natives,  the  type  of  tuberculosis  is  that 
of  an  old,  well-tuberculized  community.  A  remedy  for  its 
great  prevalence  is  therefore  to  be  sought  in  improvements 
in  sanitation  and  the  cure  of  occult  infections  rather  than 
in  measures  addressed  to  the  protection  of  as  yet  uninfected 
adults. 

In  Guam  Odell3  states  that  pulmonary  tuberculosis  is  very 
common  and  fatal,  but  furnishes  no  statistics.  Knee-joint 
tuberculosis  is  frequent  in  children,  as  is  also  intestinal 
tuberculosis.  The  mesenteric  glands  are  involved  in  many 
cases  and  tuberculosis  of  the  cervical  glands  is  common  in 

1  Ann.  d'Hyg.  et  Med.  Colon.     Vol.  6,  1903,  p.  597. 

2  Arch,  de  Med.  Navale.    Vol.  30,  1878,  p.  226. 

8  Tropical  iS'urgery  and  Diseases  of  the  Far  East.    McDill. 


50  EPIDEMIOLOGY   OF  TUBERCULOSIS 

young  adults  and  in  children.  The  incidence  of  amebic 
dysentery,  which  is  a  common  disease,  has  been  much  re- 
duced since  the  introduction  of  a  water-supply  system  and 
the  closing  of  the  surface  wells.  There  is  no  typhoid  fever 
nor  malaria  on  the  island.  Intestinal  parasites  are  found 
in  almost  one  hundred  per  cent,  of  the  natives. 

On  an  island  which  has  long  been  a  Spanish  colony  a 
fairly  complete  tuberculization  of  the  natives  is  to  be  ex- 
pected, and  this  is  shown  to  be  the  case  by  the  type  of  tuber- 
culosis in  the  young,  that  is,  the  involvement  of  glands  and 
joints,  and  also  by  the  fact  that  the  fatal  tuberculosis  is 
pulmonary  tuberculosis.  It  is  to  be  expected  that  one  of 
the  benefits  of  the  improved  water-supply  will  prove  to  be 
a  reduction  in  the  tuberculosis  mortality. 

According  to  Cottle1  pulmonary  tuberculosis  is  present  in 
American  Samoa,  about  twelve  cases  having  been  detected 
in  some  3000  cases  of  disease  seen  in  one  year.  Two  cases 
of  healed  joint  tuberculosis  are  known.  Pott's  disease  is 
present  in  about  20  old  cases  in  the  population.  Tubercu- 
lous glands  of  the  neck  are  quite  common.  Six  deaths  of  a 
total  of  300  deaths  in  children  were  due  to  meningitis. 
Three  of  these  are  believed  to  have  been  tuberculous.  There 
is  no  typhoid  fever  nor  malaria.  Bacillary  dysentery  is 
common  but  never  fatal  unless  mistreated.  It  is  ascribed 
to  the  eating  of  decayed  food  or  to  overeating  at  feasts.  An 
epidemic  of  measles  in  1910  attacked  practically  every  one 
under  the  age  of  nineteen  years  and  was  fatal  in  about  eight 
per  cent,  of  the  cases.  Dysentery  during  convalescence  is 
stated  to  have  been  the  cause  of  death.  Intestinal  para- 
sites are  very  common:  uncinaria,  trichuris,  oxyuris,  ver- 
micularis.  It  is  probable  that  every  native  child  carries 
the  ascaris  and  every  adult  the  hookworm,  most  of  them 


1  Trop.  Surgery  and  Diseases  of  the  Far  East. 


TUBERCULIZED  RACES  51 

also  the  trichuris.  Examination  of  70  men  picked  for  their 
good  hygienic  surroundings,  all  of  them  members  of  the 
native  guard  who  live  in  barracks,  showed  that  all  had  hook- 
worm, nearly  all  the  whipworm  and  a  few  the  ascaris. 
Only  about  ten  per  cent,  of  the  native  population,  according 
to  Cottle,  show  marked  effects  from  this  cause,  probably, 
he  says,  because  of  an  abundance  of  food  and  a  small 
amount  of  hard  work  which  nearly  make  up  for  losses  occa- 
sioned by  the  parasites.  All  the  children  have  yaws,  as  a 
rule,  at  the  age  of  three  to  five  years.  The  mother  is  will- 
ing to  expose  her  child  to  infection  because  she  believes  it 
inevitable  and  thinks  it  better  for  the  child  to  have  the  dis- 
ease in  early  life.  Trichophytosis  and  certain  forms  of  con- 
junctivitis are  very  common. 

Missionaries  have  been  in  Samoa  since  18301  and  no  doubt 
the  islands  were  frequently  visited  by  traders  before  that 
date.  After  such  a  prolonged  contact  with  civilization 
tuberculization  of  the  native  population  is  to  be  expected 
and  we  learn  in  fact  that  the  type  of  tuberculosis  present 
is  the  type  with  which  we  are  familiar  in  long  civilized 
communities  —  tuberculosis  of  the  lungs,  of  the  bones  and 
of  the  cervical  glands  —  with  in  addition  some  tuberculous 
meningitis,  showing  that  in  Samoa  as  elsewhere  some  of 
the  children  are  exposed  to  massive  tuberculous  infections. 
But  what  excites  surprise  is  the  small  amount  of  and  pre- 
sumably the  small  mortality  from  pulmonary  tuberculosis. 
In  a  population  of  about  7000,  3000  cases  of  disease  must 
represent  practically  the  total  amount  of  sickness.  It  is 
not  therefore  probable  that  many  cases  of  pulmonary  tuber- 
culosis escape  detection,  and  we  must  explain  their  small 
number  either  by  the  absence  of  opportunity  for  infection 
or  by  the  good  health  and  good  hygiene  of  the  population. 

1  Leber  and  Prowazek,  Arch.  f.  Sehiffs-u.  Tropenhyg.    Vol.  15,  1911,  p.  409- 


52  EPIDEMIOLOGY   OF  TUBERCULOSIS 

The  fact  that  tuberculosis  of  the  cervical  glands  is  stated 
to  be  quite  common,  the  length  of  contact  with  civilization 
of  the  community  and  the  absence  of  remark  as  to  the  oc- 
currence of  acutely  fatal  tuberculosis  in  adults  makes  the 
first  hypothesis  improbable  and  it  will  be  of  interest  to 
hear  Surgeon  Cottle  farther  as  to  the  health  conditions  in 
Samoa.  American  Samoa,  he  says,  is  situated  14°  south 
of  the  equator.  The  temperature  is  very  equable,  there 
being  a  difference  of  only  two  or  three  degrees  between 
day  and  night  and  only  eight  or  ten  degrees  between  sum- 
mer and  winter.  The  rainfall  is  often  more  than  275 
inches  in  the  year,  yet  the  humidity  is  seldom  high  enough 
to  affect  the  health.  The  Samoan  Islands  are  so  isolated 
(three  days  steaming  from  their  nearest  neighbors)  that 
they  are  remarkably  free  from  the  common  contagious  and 
infectious  diseases.  The  native  eats  the  cocoanut,  banana, 
breadfruit  and  taro,  a  vegetable  diet  which  gives  him  health 
and  strength  well  above  the  average.  Fish,  pork  and  salt 
meats  are  the  occasional  luxuries  added  in  times  of  feast- 
ing. The  Samoan  is  vigorous,  robust  and  well-developed. 
He  can  row  40  to  60  miles  a  day  without  fatigue  and  can 
travel  miles  with  a  heavy  burden  on  his  back.  He  can 
show  a  surprising  energy  and  muscular  endurance  in  his 
native  dance  and  can  accomplish  a  great  deal  of  work  m 
the  fields.  Isolation  from  contact  with  other  races,  gov- 
ernment protection  from  commercial  exploitation,  an 
abundance  of  good  food,  carefully  prepared  and  well  cooked, 
a  good  water  supply,  an  outdoor  life,  well  built  houses,  an 
equable,  warm  climate,  cleanly  personal  habits  and  a  very 
normal  type  of  sexual  life  are  conditions  all  of  which  com- 
bine to  make  the  Samoan  a  healthy  animal.  Were  it  not 
for  the  presence  of  a  few  parasitic  and  infectious  diseases 
which  affect  large  numbers  of  the  population  —  one  indi- 


TUBERCULIZED  RACES  53 

vidual  often  harboring  two  or  more  infections  —  sickness 
would  be  almost  unknown  among  them.  For  the  native  the 
climate  seems  to  be  practically  perfect.1  Such,  somewhat 
abridged,  is  the  account  of  an  eye-witness. 

The  conditions  in  Samoa  as  to  tuberculosis  are  of  course 
by  no  means  ideal.  There  should  be  no  meningitis  of  in- 
fants nor  scrofulous  glands  in  the  necks  of  the  adolescents. 
The  dosage  of  tuberculous  virus  is  evidently  larger  than  is 
desirable  for  vaccination  and  the  personal  hygiene  and 
housing-conditions  are  no  doubt  not  above  criticism.  Yet 
the  results  reached  are,  it  would  appear,  so  much  better 
than  those  of  our  own  civilization  that  there  is  no  compari- 
son between  them.  And  this  in  a  people  in  which  every 
adult  harbors  the  hookworm  and  every  child  has  the  yaws ! 

It  was  to  such  an  Arcadia  as  Samoa  that  the  French  gov- 
ernment thought  to  convey  its  charges  when  it  established 
the  penal  colony  at  New  Caledonia.  But  how  great  the  dif- 
ference in  results!  We  do  not  know  the  local  conditions 
sufficiently  to  speak  with  any  degree  of  positiveness  as  to 
the  reasons  for  the  marked  prevalence  of  tuberculosis 
among  the  immured  convicts.  But  there  are  some  salient 
contrasts  between  the  life  of  the  natives  at  the  two  places. 
The  French  writers  paint  a  dark  picture  of  the  moral  con- 
ditions at  New  Caledonia.  At  Samoa  there  is  no  prostitu- 
tion and  alcoholism  and  drug  habits  are  practically  un- 
known, the  importation  of  drugs  or  patent  medicines  with- 
out express  authority  and  the  sale  of  alcohol  to  the  native 
being  forbidden  by  law.  While  it  is  not  believed  that  the 
Samoan  is  a  stern  moralist  according  to  our  ideas,  he  with- 
out doubt  leads  a  more  healthful  life  —  possibly  in  part 
because  he  can  not  do  otherwise  —  than  the  native  of  New 

1  Robert  Louis  Stevenson,  "Letters."  Vol.  2,  p.  333,  eays:  "Take  it 
for  all  in  all,  I  suppose  this  island  climate  to  be  by  far  the  healthiest  in 
the  world." 


54  EPIDEMIOLOGY   OF  TUBERCULOSIS 

Caledonia,  whom  the  discharged  convict,  an  outcast  from 
French  society,  seeks  to  share  his  debaucheries  and  alco- 
holic excesses.  A  drunken  and  debauched  population  may 
be  decimated  by  tuberculosis  and  uncinariasis  singly  or 
combined  though,  as  it  would  seem,  another  people  living 
under  practically  identical  climatic  conditions  but  with 
better  hygiene  may  find  the  two  scourges  not  incompatible 
with  vigorous  health,  so  far  as  the  great  majority  of  the 
population  is  concerned.  It  is  greatly  to  be  desired  that  a 
survey  should  be  made  with  the  aid  of  the  von  Pirquet 
reaction  in  order  to  determine  what  the  degree  of  tubercu- 
lization of  the  Samoan  population  really  is. 

Tuberculosis  is  said  to  be  frequent  in  the  towns  of  Porto 
Rico.  The  statistics  of  the  total  incidence  of  tuberculosis 
should  however  be  received  with  caution  because  it  has 
sometimes  been  the  practice  to  include  cases  of  sprue  under 
the  caption  "  intestinal  phthisis  ".  The  form  of  tuberculo- 
sis which  prevails  is  chiefly  chronic  pulmonary  tuberculo- 
sis. Tuberculosis  of  bones  and  joints  is  excessively  rare 
and  glandular  tuberculosis  infrequently  demands  surgical 
intervention.  In  the  country  districts  tuberculosis  is  not 
a  common  disease.  A  report  to  this  effect  was  made  by  the 
Anemia  Commission  in  19041  and  this  view  is  reaffirmed 
in  the  report  of  the  Institute  of  Tropical  Medicine  and 
Hygiene  of  1914.2  In  1913  an  expedition  into  the  interior 
was  organized  for  the  purpose  of  studying  all  diseases, 
medical  and  surgical,  which  might  present  themselves  in 
the  region  selected,  which  was  in  the  vicinity  of  the  town 
of  Utuado.  The  force  consisted  of  three  members  of  the 
Institute  with  the  collaboration  of  Major   (now  Colonel) 

'Report  of  the   Porto  Rico  Anemia  Commission,   1904. 

:  Report  of  the  Utuado  Expedition.  (Reports  and  Collected  Studies  from 
Institute  of  Tropical  Medicine  and  Hygiene  of  Porto  Rico.  Vol.  1,  1913- 
1917,  p.  35.) 


TUBERCULIZED  RACES  55 

Bailey  K.  Ashford,  Medical  Corps,  U.  S.  Army,  President 
of  the  Board  for  the  study  of  Tropical  Diseases  of  Porto 
Rico,  and  one  volunteer  assistant,  in  all  five  physicians. 
Four  other  physicians  belonging  to  the  Anaemia  Service 
Insular  Service  Sanitation,  were  associated  with  the  Board 
of  the   Institute.     It  was   intended   to   devote   a   certain 
amount  of  time  to  visiting  the  sections  from  which  patients 
came  but  inasmuch  as  the  personnel  of  the  Institute  was 
known  to  the  country  people  from  a  previous  expedition  tc 
that  region  nine  years  before,  an  ever-increasing  number 
of  patients  thronged  the  clinic  that  had  been  established 
two  miles  from  Utuado  and  made  the  realization  of  the  in- 
tention practically  impossible.     In  all  10,140  patients  were 
examined  in  60  working  days,  of  which  about  2500  were 
admitted  to  the  general  clinic,  but  only  1923  were  made  sub- 
jects of  record,  the  remainder  being  clearly  ordinary  cases 
of  uncinariasis.     Generally  all  cases  of  chronic  cough  elic- 
ited a  microscopic  examination  of  the  sputum.     Pulmonary 
tuberculosis  was  found  as  the  principal  cause  of  disease  in 
56  cases  and  was  suspected  to  be  present  in  11  additional 
cases.    Cervical  adenitis  was  the  principal  cause  of  dis- 
ease in  9  cases,  axillary  in  3,  inguinal  in  1.     There  were  3 
cases  of  tuberculous  hip  joint  disease  and  three  of  ganglion. 
The  majority  of  the  tuberculous  cases  came  from  the  town 
of  Utuado.     Eight  of  the  cases  registered  died  in  Utuado 
during  the  ten  weeks  devoted  to  the  examination.     The 
county  in  which  Utuado  is  situated  has  43,000  inhabitants, 
the  town  itself  about  6000.     Of  the  10,140  cases  about  76 
per  cent,  were  found  infected  with  uncinariasis.     On  ac- 
count of  the  high  professional  standing  of  these  investiga- 
tors their  results,  though  imperfect  so  far  as  relates  to 
tuberculosis,  have  been  given  in  some  detail.     Some  allow- 
ance should  possibly  be  made  for  the  fact  that  the  work  of 


56  EPIDEMIOLOGY   OF  TUBERCULOSIS 

the  Institute  would  be  particularly  connected  with  uncinaria- 
sis by  the  people,  so  that  it  might  be  anticipated  that  the 
sufferers  from  hookworm  would  present  themselves 
especially.  And  they  would  not  be  likely  to  bring  with 
them  cases  of  advanced  tuberculosis  on  sometimes  long 
and  even  dangerous  trips  over  mountain  trails,  nor  when 
the  daily  attendance  averaged  some  600  persons,  could  it  be 
expected  that  slight  or  incipient  cases  of  pulmonary  tuber- 
culosis would  all  be  detected.  Making  allowance  for  such 
sources  of  error,  it  would  seem  that  the  incidence  of  tuber- 
culosis among  the  countryfolk  of  Porto  Rico  is  small.  Ash- 
ford  had  four  per  cent,  of  tuberculosis  among  his  own 
patients  in  city  and  country,  numbering  about  4000  cases, 
and  sixty  per  cent,  of  chronic  bronchitis.  The  sputum  of 
all  his  lung  cases  was  examined  for  the  tubercle  bacillus. 
The  Porto-Rican  regiment  appears  to  have  a  small  inci- 
dence of  tuberculosis.  Its  numbers  are  too  small,  however, 
to  give  ratios  of  any  value  for  statistical  purposes. 

The  question  whether  the  apparent  relative  infrequency 
of  manifest  tuberculosis  in  the  rural  districts  is  due  to  a 
successful  immunization  of  the  population  or  to  the  ab- 
sence of  opportunities  for  infection  is  a  very  important 
one.  For  the  latter  supposition  speak  the  often  acute  type 
of  the  disease  when  present  and  the  prevalence  of  a  very 
severe  uncinariasis  which,  according  to  the  prevailing  ideas, 
would  tend  to  break  down  the  resistance  of  the  already 
infected  individual  and  favor  the  development  of  manifest 
tuberculosis.  The  coffee  plantations  of  Porto  Rico  appear 
to  be  ideal  places  for  massive  infections  with  hookworm. 
The  average  number  of  hookworms  per  patient  in  the  south- 
ern United  States  is  stated  to  be  twenty,  but  in  Porto  Rico 
it  is  one  thousand.1     Hence  the  very  severe  type  of  anemia 

'Colonel  Ashford.     Personal   communication. 


TUBERCULIZED  RACES  57 

which  prevails  in  the  country  districts  and  almost  totally 
disables  the  affected  individuals  for  manual  labor.  On  the 
other  hand,  judging  from  analogy,  it  is  to  be  expected  that 
an  old  settled  community  will  have  a  fairly  complete  tuber- 
culization. An  extended  survey  here  by  means  of  the 
tuberculin  cutaneous  test  would  certainly  furnish  very  in- 
teresting and  valuable  results. 

Though  in  many  respects  the  data  furnished  are  defec- 
tive, the  foregoing  examples  of  communities,  civilized  and 
semi-civilized,  in  which  tuberculosis  has  long  prevailed 
afford  some  idea  as  to  the  type  of  the  disease  which  may 
be  expected.  In  all  the  prevailing  type  is  chronic  pulmo- 
nary tuberculosis  which  may  pursue  a  very  sluggish  course ; 
tuberculosis  of  bones,  joints  and  glands,  chronic  condi- 
tions, occur  with  more  or  less  frequency.  The  morbidity 
is  evidently  often  high,  the  rate  of  mortality,  as  a  rule  un- 
determined and  no  doubt  undesirably  high,  is  apparently 
not  alarming.  Where  statistics  are  available  it  appears 
that  improvement  in  sanitation  effects  a  lowering  in  the 
mortality  from  tuberculosis. 


CHAPTER  IV 
NON-TUBEBCULIZED  RACES 

Very  different  is  the  picture  when  the  natives  of  a  tropi- 
cal country  first  come  into  contact  with  an  older  civiliza- 
tion. V 

Buisson1  says  of  the  Marquesas :  "  Tuberculosis  is  now 
very  widespread.  It  has  depopulated  many  valleys.  It 
evolves  with  great  rapidity.  When  the  malady  attacks  one 
of  the  unhealthful  huts  where  swarm  pellmell  eight  or  ten, 
even  twelve  or  fifteen  persons,  it  is  quickly  emptied.  In 
less  than  two  years,  sometimes  in  one  year,  the  house  is 
vacant  —  all  of  its  inhabitants  are  in  the  cemetery.  The 
population  has  considerably  diminished  and  will  soon  dis- 
appear, if  a  remedy  is  not  found  '*r  Robert  Louis  Steven- 
son2 says :  "  The  Marquesan  race  is  perhaps  the  hand- 
somest extant.  Six  feet  is  about  the  middle  height  of 
males;  they  are  strongly  muscled,  free  from  fat,  swift  in 
action,  graceful  in  repose.  To  judge  by  the  eye,  there  is  no 
race  more  viable;  and  yet  death  reaps  them  with  both 
hands.  When  Bishop  Dordillon  first  came  to  Tai-o-hae,  he 
reckoned  the  inhabitants  at  many  thousands;  he  was  but 
newly  dead,  and  in  the  same  bay  Stanislao  Moanatini 
counted  on  his  fingers  eight  residual  natives  .«:N  The  tribe  of 
Hapaa  is  said  to  have  numbered  some  four  hundred,  when 
the  small-pox  came  and  reduced  them  by  one-fourth.  Six 
months  later  a  woman  developed  tubercular  consumption; 
the  disease  spread  like  a  fire  about  the  valley,  and  in  less 
than  a  year  two  survivors,  a  man  and  a  woman,  fled  from 
that  new-created  solitudes   A  similar  Adam  and  Eve  may 


1  Ann.  d'Hyg.  et  MeU  Colon.     Vol.  6,  1903,  p.  535. 

2  In  the  South  Seas.     1908,  p.  33. 

58 


NON-TUBERCULIZED  RACES  59 

some  day  wither  among  new  races,  the  tragic  residue  of 
Britain.  When  I  first  heard  this  story  the  date  staggered 
me;  but  I  am  now  inclined  to  think  it  possible.  Early  in 
the  year  of  my  visit,  for  example,  or  late  the  year  before,  a 
first  case  of  phthisis  appeared  in  a  household  of  seventeen 
persons,  and  by  the  month  of  August,  when  the  tale  was 
told  me,  one  soul  survived,  and  that  was  a  boy  who  had  been 
absent  at  his  schooling  ". 

Similarly  McCarthy  reports  from  Panama  that  tubercu- 
losis plays  havoc  there  with  the  mixed  tropical  races,  whole 
families  being  sometimes  infected  simultaneously  in  their 
unhealthful  huts  to  the  complete  extermination  of  groups 
of  natives.1  From  the  German  West  Carolinas  it  is  re- 
ported that  Yap  is  being  depopulated  by  tuberculosis.2 
A  census  shows  that  the  older  people  are  in  the  majority, 
some  of  the  years  of  youth  not  being  represented  at  all. 
The  young  people  have  melted  away  in  the  last  few  years 
with  tuberculosis,  having  also  been  carried  off  in  part  with 
dysentery.  Here,  however,  the  tuberculosis  was  not 
strictly  primary,  otherwise  there  would  have  been  no  dis- 
tinction as  to  the  age  of  the  victims. 

According  to  Calmette,3  an  English  speculator  once  intro- 
duced into  Lima  2000  natives  of  the  Marquesas.  Three- 
fourths  of  these  were  dead  of  tuberculosis  in  less  than  18 
months. 

In  1803  and  1810  the  British  government  imported  some 
three  or  four  thousand  negroes  from  Mozambique  into 
Ceylon  to  form  regiments.  Of  these  there  were  left  in 
1820  but  440,  including  male  descendants.  Bartolocci,  ac- 
cording to  Hirsch,  says  that  9000  Kaffirs  brought  to  Ceylon 

Boston  Med.  and  Surg.  Jour.    Vol.  166,  1912,  p.  207. 

2  Mayer,  loc.  cit. 

•Ami.  de  l'lnstitut  Pasteur.     Vol,  26,  1912,  p.  207. 


60  EPIDEMIOLOGY   OF   TUBERCULOSIS 

by  the  Dutch  government  and  put  into  military  service,  left 
no  trace  by  which  their  descendants  can  be  recognized  in 
the  present  population. : 

In  Queensland  the  mortality  of  the  whites  from  tubercu- 
losis is  low.  notwithstanding  the  fact  that  consumptives 
from  England  resort  there  on  account  of  the  favorable  cli- 
mate. Yet  according  to  Jeanselme  and  Past,  tuberculosis 
is  murderous  among  the  Polynesians,  who,  while  they  make 
up  but  two  per  cent,  of  the  population,  furnish  twenty-two 
per  cent,  of  the  mortality  from  tuberculosis. 

From  an  account  by  a  physician  published  in  19102  it 
appears  that  the  island  of  Tierra  del  Fuego,  until  about  30 
years  before  the  article  was  written,  was  inhabited  exclu- 
sively by  native  Indians.  The  discovery  of  gold  and  later 
sheep-farming,  brought  Europeans,  mostly  English,  to  the 
island.  Although  the  Indians  possessed  no  fire-arms,  they 
nevertheless  attempted  to  resist  the  encroachments  of  the 
whites,  and  many  of  them  were  killed  in  the  unequal  strife. 
But  in  addition  to  losses  in  warfare  the  Indians  perished  in 
large  numbers  in  part  from  syphilis  and  alcohol,  but  the 
greater  number  from  tuberculosis. 

A  Catholic  order  was  given  the  use  of  a  small  uninhab- 
ited island  by  the  Chilian  government  with  a  view  to 
'*  Christianize  "  the  natives  of  Tierra  del  Fuego  there  and 
to  put  an  end  to  the  ceaseless  combats.  So  far  as  the 
Indians  could  be  laid  hold  of  they  were  transported  to  this 
island,  the  number  sent  being  estimated  at  about  2000. 
Here  they  were  put  to  work  on  a  sheepfarm,  were  compelled 
to  wear  European  clothing,  and  were  crowded  into  ill  ven- 
tilated huts.     The  result  was  devastation  by  tuberculosis. 

'Handbuch  der  Historisch-geographisehen  Pathologie.     Vol.  2,  1862-1S64, 
p.  74. 

2 "Dr.  D."\  Miinc-h.  Med.  Wochenscbr.     Vol.  L  1910,  p.  1075. 


NON-TUBERCULIZED  RACES  61 

In  three  years  only  a  few  dozen  Indians  remained  alive.  A 
priest  relates  that  of  about  200  captured  Indians,  48  died 
of  tuberculosis  in  a  single  month.  The  writer  remarks 
that  it  is  no  exaggeration  to  say  that  every  native  Tierra 
del  Fuegan  who  comes  permanently  in  contact  with  the 
whites  dies  of  pulmonary  tuberculosis,  and  says  that  the 
course  of  the  tuberculosis  is  extraordinarily  rapid.  "  When 
the  first  certain  signs  of  the  disease  are  found  in  the  lungs 
it  may  safely  be  assumed  that  the  patient  will  die  within 
six  weeks  ".  The  total  number  of  Indians  was  estimated 
at  5000  when  white  men  first  settled  upon  the  island.  Of 
these  barely  300  remained  in  1910.  It  is  probable  that  the 
race  will  soon  become  extinct.  Tuberculosis  does  not  occur 
among  the  whites  more  frequently  than  in  Europe,  and  is 
of  the  usual  type.  The  climate,  though  harsh,  seems  to  be 
a  healthful  one  for  Europeans.  The  natives  say  that  be- 
fore the  whites  arrived  old  age  was  the  only  cause  of  death. 

The  foregoing  facts  illustrate  the  terrible  effects  of  tuber- 
culosis when  large  numbers  of  the  unprotected  are  subjected 
to  massive  infections,  especially  when  under  bad  hygienic 
conditions,  the  disease  then  prevailing  as  an  epidemic  and 
sweeping  off  nearly  every  one  who  has  been  exposed  to  it.1 

Unless  the  race  is  exterminated,  however,  it  undergoes  a 
process  of  tuberculization  through  decades  or  centuries,  the 
disease  becoming  gradually  more  chronic  and  less  severe, 
until  finally  under  favorable  conditions  a  stage  of  immuni- 
zation is  reached  comparable  to  that  which  prevails  in  the 
most  highly  civilized  peoples.  American  Samoa  seems  to 
be  a  case  in  point.  In  Tahite  and  Hawaii  also  the  formerly 
acutely  fatal  types  of  tuberculosis  have  largely  disap- 
peared, as  the  tuberculization  of  the  people  has  become 
more  complete. 

1  Compare  also  pages  75,  109,  160,  162,  165  and  167. 


CHAPTER  V 
MODES  OF  INFECTION 

It  is  customary  to  attempt  to  explain  tuberculous  infec- 
tion by  contact  with  the  consumptive,  but  there  are  so  many 
cases  in  which  the  history  gives  no  assistance  whatever  in 
pointing  out  the  source  of  the  infection  that  it  is  evident 
that  we  must  look  beyond  immediate  contact  with  cases  of 
open  tuberculosis  or  their  infected  surroundings,  to  account 
for  the  practically  universal  dissemination  of  the  tubercle 
bacillus  under  the  conditions  of  civilization.  Experience 
shows  that  children  who  live  with  a  consumptive  are  likely 
to  have  a  more  severe  form  of  tuberculous  infection  than 
that  of  those  whose  sources  of  infection  are  unknown.  This 
may  be  explained,  no  doubt,  in  part  at  least,  by  the  supposi- 
tion that  the  latter  receive  a  smaller  amount  of  the  infec- 
tious organisms,  but  it  is  by  no  means  improbable  that 
attenuation  of  the  tubercle  bacilli  also  plays  a  role  here. 
It  should  be  remembered  that  the  tubercle  bacilli  retains 
its  vitality  almost  indefinitely  if  not  exposed  to  direct  sun- 
light, but  that  its  virulence  is  somewhat  reduced  by  dessi- 
cation.  There  is  always  the  chance  that  the  living  bacillus 
may  reach  the  hands  and,  secondarily,  too  often  the  mouth 
of  the  uninfected  child  from  some  article  in  common  use 
that  has  been  touched  by  the  infected  hands  of  the  con- 
sumptive (or  the  tuberculosis  carrier).  Some  of  such 
articles  which  are  practically  never  disinfected  are  wooden 
toys,  books  (especially  of  schools  and  public  libraries), 
shoes,  and  other  articles  of  leather,  clothing,  coins  and  bills, 
bread,  cake  and  candy  from  the  shops,  the  paper  and  string 
used  for  wrapping  parcels,  postage  stamps   (laid  face  up 

62 


MODES  OF  INFECTION  63 

upon  a  possibly  infected  counter  without  regard  to  the  fact 
that  their  adhesive  surface  is  admirably  adapted  to  pick 
up  germs  of  disease) ,  letters  received  through  the  mails 
(both  envelopes  and  contents),  the  doorknobs  of  public 
buildings,  the  handrails  of  trolley  and  steam  cars,  dust  from 
the  street  deposited  on  the  floor  and  adhering  to  dropped 
articles,  etc.,  etc.  When  we  consider  that  in  order  that 
infection  may  take  place,  it  is  only  necessary  that  the 
mouth  shall  have  been  contaminated  once  in  the  course  of 
years  from  one  of  the  articles  above  enumerated,  some  or 
all  of  which  are  handled  every  day  by  most  people,  it  would 
appear  that  infection  could  hardly  be  escaped. 

But  there  is  another  possible  source  of  infection  which  is 
rarely  taken  into  consideration.  Calmette,1  basing  his 
ideas  upon  the  results  of  his  extensive  experiments  with 
cattle,  claims  that  since,  as  he  has  shown,  tubercle  bacilli 
which  circulate  in  the  blood  of  tuberculous  cattle  are  elimi- 
nated with  the  bile  by  the  way  of  the  intestine,  it  is  alto- 
gether probable  that  the  bacilli  of  human  tuberculosis  are 
eliminated  in  the  same  manner.  It  has  been  shown  that 
bacteremia  may  be  present  in  cases  not  clinically  tubercu- 
lous and  it  is  also  known  that  tubercle  bacilli  may  be  found 
in  the  faeces  in  cases  of  tuberculous  disease  of  the  bones  or 
joints,  the  lungs  and  alimentary  canal  being  free,  so  far  as 
can  be  determined  during  life,  of  tuberculosis.  The  subject 
requires  farther  investigation,  no  doubt,  but  the  probabili- 
ties are  in  favor  of  the  assumption  that  every  individual 
who  harbors  tubercle  bacilli  is  a  tuberculosis  carrier  who 
may  at  times  excrete  tubercle  bacilli  by  way  of  the  intestine. 
We  know  what  it  means  to  the  household  if  the  cook  is  a 
typhoid-carrier,  and  what  extreme  care  is  necessary  for  the 
safe  disinfection  of  the  hands  of  those  who  have  to  do  with 

1  Loc.  cit. 


64  EPIDEMIOLOGY   OF  TUBERCULOSIS 

typhoid  fever.  Such  care  is  naturally  never  taken  by  the 
tuberculosis-carrier,  who  regards  himself  as  a  healthy  per- 
son. If  those  "  vaccinated  "  against  tuberculosis  are  tuber- 
culosis-carriers, the  fact  which  puzzles  some  writers  is  ex- 
plained, namely  that  though  no  cases  of  open  tuberculosis 
are  present,  contact  on  the  part  of  the  unprotected  savage 
with  Europeans,  Hindoos  or  Chinese  sooner  or  later  leads 
to  infection  with  tuberculosis. 

With  regard  to  the  possibility  of  the  infection  of  tubercu- 
losis being  communicated  to  others  by  those  who  apparently 
were  without  disease  at  the  time,  there  is  an  interesting 
analogy  in  leprosy.  Speaking  of  the  long  incubation  period 
of  that  disease,  Babes  says :  "  We  would  only  insist  that 
the  peculiar  febrile  phenomena  and  eruptions  which  pre- 
cede the  true  disease,  often  by  many  years,  speak  for  the 
fact  that  the  bacillus  does  not  remain  entirely  inactive,  but 
increases  in  number  from  time  to  time  and  probably  pro- 
duces fever-making  substances.  I  have  also  been  able  to 
make  out  that  sometimes  certain  deep  lymph-glands  may 
show  changes  many  years  old,  evidently  much  older  than 
the  manifest  leprosy.  One  can  not  reject  the  idea  that  even 
in  this  stage,  under  some  circumstances,  infection  can  result 
for  there  are  cases  in  which  it  is  stated  that  individuals 
have  become  leprous  who  had  been  in  contact  with  others 
who  came  from  lepra-regions  but  without  being  leprous, 
the  disease  not  manifesting  itself  in  these  latter  until  a  later 
time  'V 

The  practice  among  civilized  peoples  of  handling  con- 
stantly many  objects  which  have  passed  through  unknown 
hands  has,  then,  the  advantage  that  it  tends  to  facilitate 
infection  with  tuberculosis  by  means  of  comparatively  few 


Die  Lepra,  Nothnagel's  Spezielle  Pathologie  u.  Therapie.    Vol.  24,  p.  58. 


MODES  OF  INFECTION  65 

bacilli  attenuated  by  drying  and  age.  The  uncivilized  eat 
out  of  a  common  dish,  pass  the  tobacco  pipe  from  hand  to 
hand,  lie  down  at  night  in  close  contact  on  ground  fouled 
with  expectoration.  The  conditions  are  ideal  for  the  fur- 
ther propagation  of  tuberculosis,  once  it  is  introduced, 
hence,  in  part,  the  epidemic  character  of  the  disease.  On 
the  other  hand  the  tropical  native  makes  much  less  use  of 
articles  of  commerce  than  the  civilized.  He  is  not  so  likely, 
therefore,  to  get  his  primary  infection  from  a  few  attenu- 
ated bacilli.  Living  in  a  narrow  circle  he  may  long  escape 
infection  altogether,  but  when  it  comes,  it  will  probably 
have  been  derived  from  personal  contact  of  some  kind  and 
will,  therefore,  be  more  massive  and  more  virulent.  But 
no  doubt  the  unprotected  adult  may  and  often  does  obtain 
a  "  vaccination  "  from  his  first  infection. 

With  reference  especially  to  the  question  as  to  the  possi- 
bility of  immunizing  the  unprotected  adult  by  means  of  his 
first  infection,  the  experience  of  Much  in  Jerusalem  and 
the  conclusions  that  he  draws  from  it  are  of  interest.  They 
also  corroborate  in  a  helpful  way  the  lessons  derived  from 
the  study  of  tropical  tuberculosis. 

Much  made  an  investigation  of  the  tuberculosis  situation 
in  Jerusalem  and  tested  many  of  the  inhabitants  by  means 
of  the  cutaneous  reaction  to  tuberculin.  He  draws  his  con- 
clusions as  follows  i1 

"  If  we  test  people  who  have  recently  come  from  Yemen, 
we  find  that  those  born  in  Arabia  react  negatively,  but  the 
case  is  quite  different  with  those  who  have  lived  some  time 
in  Jerusalem.  Here  we  found  positive  reactions  in  almost 
90  per  cent,  and  beginning,  even,  in  earliest  childhood.  Those 
who  react  almost  always  have  some  (manifest)  tuberculous 

1  Beitr.  z.  Klinik  d.  Tub.     Sixth.  Supplementary  Vol.,  p.  25. 


66  EPIDEMIOLOGY  OF  TUBERCULOSIS 

affection  in  contrast  with  the  positively  reacting  Jews  of 
other  races  and  the  Europeans.  Thus  it  is  explained  why 
in  the  Yemenites  the  disease  is  a  pestilence,  which  fs  not  the 
case  in  the  European  Jews,  who  react  positively  in  a  high 
percentage.  The  explanation  is  the  same  as  has  been  given 
for  the  appearance  of  the  disease  as  an  epidemic  in  all  races 
and  regions  hitherto  free  of  tuberculosis.  In  Europe, 
tuberculosis  is  a  child's  disease.  Almost  every  European 
receives  tubercle  bacilli  in  childhood  and  is  thereby  either 
infected  or  immunized.  The  adult  is  protected  against  a 
second  infection  coming  from  without.  If  he  dies  it  is 
from  the  disease  of  childhood,  i.  e.,  from  the  tubercle  bacilli 
acquired  when  a  child.  For  the  Jews  from  Europe  the  con- 
ditions in  Palestine  are  similar.  With  the  Yemenites  and 
all  the  sub-races  which  come  from  regions  free  of  tubercu- 
losis the  case  is  different.  They  are  in  the  greatest  danger, 
and  this  is  true  also  of  the  Arabs.  With  them  tuberculosis 
is  not  a  child's  disease.  There  has  been  no  contact  with 
tuberculosis,  therefore  no  immunization.  There  the  adult 
is  in  the  same  condition  as  the  not  yet  immunized  child. 
The  question  why  the  immigrating  adult  can  not  immunize 
himself  as  the  child  does  in  Europe  is  probably  to  be 
answered  by  saying  that  he,  going  about  freely,  always 
comes  in  contact  with  large  amounts  of  tubercle  bacilli 
which  can  not  be  resisted,  while  the  child  is  limited  in  his 
movements." 

We  see  here  again  that,  as  was  the  case  with  the  Polyne- 
sian, it  is  not  a  question  of  racial  susceptibility  or  immu- 
nity.1 The  Jews  generally  show  great  resistance  to  tuber- 
culosis, yet  the  Jews  born  in  Arabia  have  no  defense  against 
the  disease.     For  them  tuberculosis  is  "  pestilential,"  be- 

1  According  to  some  authorities,  however,  the  Jews  of  Yemen  are  racially 
Arabs  who  have  adopted  Judaism.     (Fishberg,  The  Jews,  p.  124.) 


MODES  OP  INFECTION  67 

cause  they  have  had  no  opportunity  to  develop  an  immunity 
before  coming  into  contact  with  massive  infections. 

Antenatal  infection  being  extremely  rare,  it  may  be  as- 
sumed that  the  human  infant  begins  life  free  of  tubercu- 
losis. The  world  of  the  very  young  infant  is  a  narrow  one. 
Its  fate  as  to  tuberculosis  rests  in  the  hands  of  the  mother. 
The  conditions  are  such  that  if  tuberculous  infection  takes 
place  at  all,  as  when  the  mother  is  consumptive,  the  dosage 
will  probably  be  large  and  the  child  will  be  likely  to  die  of 
an  acute  generalized  tuberculosis.  If  the  child  escapes  such 
a  fate  it  will  probably  not  be  infected  until  it  is  old  enough 
to  move  about.  With  cleanly  surroundings  and  in  the  ab- 
sence of  opportunities  for  direct  infection  from  consump- 
tives, the  child  will  pick  up  now  and  then  a  tubercle  bacil- 
lus from  some  of  the  countless  articles  which  come  within 
its  reach  that  may  be  infected.  These  bacilli  reach  the 
glands  through  the  various  portals  of  infection  and  there 
are  collected  and  very  possibly  also  increased  by  multipli- 
cation until  the  threshold  of  infection  is  reached,  i.  e.,  until 
the  number  is  sufficient  to  arouse  the  specific  resistance  of 
the  organism.  The  bacilli,  coming  in  one  by  one,  in  this 
manner,  the  threshold  of  infection  will  be  passed  by  the 
smallest  number  of  bacilli  that  can  excite  a  reaction.  The 
child  thus  infected,  if  shielded  from  massive,  reinfecting 
doses,  will  proceed  to  develop  an  immunity  which  in  time 
reaches  a  maturity  such  that  no  subsequent  infection  from 
without  can  take  hold.  He  may  go  through  a  long  life 
without  developing  any  manifest  tuberculous  disease, 
though,  perhaps,  repeatedly  exposed  to  infection. 

It  should  be  emphasized  that  a  history  of  this  kind  is  the 
history  of  the  majority  of  civilized  adults.  But  if  the  ini- 
tial infection  has  been  large  or  if  there  have  been  repeated 
early  reinfections  or  if  the  resistance  of  the  individual  is 


68  EPIDEMIOLOGY  OF  TUBERCULOSIS 

lowered  by  intercurrent  disease  or  by  bad  hygiene,  the  in- 
fection with  tuberculosis  is  no  longer  simply  a  beneficent 
vaccination  but  is  in  truth  an  infection. 

On  account  of  the  bad  hygienic  conditions  in  which  the 
tropical  native  lives  he  is  more  likely  to  receive  a  too  large 
initial  infection  than  the  more  civilized  inhabitants  of  the 
temperate  zone. 

When  such  an  entirely  unprotected  organism,  whether 
infant  or  adult,  is  subjected  to  infection  from  large 
amounts  of  tubercle  bacilli,  the  result  is  a  generalized 
and  acute  disease  the  duration  of  which  is  meas- 
ured by  months  instead  of  by  years  or  decades, 
as  in  the  preceding  types.  There  is  a  certain  period 
of  incubation  —  time  is  required  for  the  multiplica- 
tion of  the  invading  bacilli  —  there  is  even  some  resistance, 
for  certain  evidences  of  attempted  localization  may  be  de- 
tected, but  no  immunity  worthy  of  the  name.  While  in 
chronic  tuberculosis  the  immunity  present  effects  charac- 
teristic localizations  of  tuberculous  lesions,  as  the  result  of 
a  more  or  less  successful  resistance  to  the  growth  and  ex- 
tension of  the  tubercle  bacillus,  the  absence  of  effective 
resistance  in  primary  tuberculosis  permits  extremely  varied 
forms  of  tuberculous  disease  the  nature  of  which,  as  found 
at  autopsy  in  the  individual  case,  is  probably  largely  de- 
pendent upon  the  size  and  number  of  the  primary  infec- 
tions and  their  portals  of  entry. 


CHAPTER  VI 

PATHOLOGY  AND  PATHOLOGICAL  ANATOMY 

Immunity  is  the  name  given  to  the  increased  resistance 
of  the  tuberculous  subject  which  is  acquired  in  the  course 
of  his  struggle  with  the  tubercle  bacillus.  Practically  ab- 
sent when  the  infection  has  been  overwhelming,  the  immu- 
nity becomes  very  marked  in  the  small  infection  in  which 
the  organism  of  the  individual  has  had  time  to  perfect  its 
defenses.  Aside,  then,  from  the  hopelessly  acute  infec- 
tions, the  study  of  the  course  of  the  tuberculous  process  is 
really  a  study  of  the  defensive  warfare  of  the  human  organ- 
ism, the  tubercle  bacilli  being  a  constant  quantity  in  the 
sense  that,  while  they  may  vary  in  virulence,  such  varia- 
tions are  due  to  increase  or  diminution  in  the  resistance  to 
which  they  are  subjected.  We  sometimes  speak,  rather 
loosely,  of  immunization  against  tuberculosis  as  a  vaccina- 
tion. The  process  bears  a  certain  resemblance  to  vaccina- 
tion against  smallpox,  but  in  some  important  respects  it 
differs  from  it.  In  the  first  place,  vaccination  is  the  inocu- 
lation of  a  virus  derived  from  and  similar  to  but 
not  indentical  with  that  of  smallpox,  but  as  yet  all 
efforts  to  produce  a  permanent  and  efficient  protec- 
tion against  tuberculosis  by  the  use  of  allied  bacilli, 
or  the  products  of  the  tubercle  bacillus  have  been 
failures.  Protection  against  tuberculosis  can  only  be  ob- 
tained from  infection  with  virulent  tubercle  bacilli  —  the 
subject  must  become  tuberculous  in  order  to  resist  tubercu- 
losis! In  the  second  place,  the  infection  is  a  continuing 
infection;  resistance  must  always  be  active,  or  must  be 
ready  to  be  active,  for  the  reason  that  the  tubercle  bacillus 
is  one  of  the  most  resistant  of  bacteria  and,  once  it  has 

69 


70  EPIDEMIOLOGY  OF  TUBERCULOSIS 

entered  the  body,  never,  as  a  rule,  becomes  extinct. 
Whereas,  in  smallpox  vaccination  the  virus,  so  far  as  we 
know,  does  not  continue  to  live,  so  that  the  effect  of  the 
vaccination,  profound  at  the  outset,  gradually  diminishes 
and  must  be  repeated  from  time  to  time  in  order  that  pro- 
tection may  be  assured.  Vaccination  against  tuberculosis 
is  therefore  more  efficient  than  vaccination  against  small- 
pox because  it  is  a  continuing  vaccination  which  persists 
through  the  life  of  the  individual  vaccinated.  If  the  fore- 
going is  correct,  does  it  not  necessarily  follow  that  the  sub- 
ject who  is  so  constantly  on  the  alert  to  resist  his  own 
bacilli  will  also  be  able  to  resist  tubercle  bacilli  which  may 
enter  his  body  from  without,  that  one  is  protected  against 
reinfection  from  any  source  outside  his  body  who  is  success- 
fully resisting  reinfection  from  the  countless  foes  within? 
Of  course,  when  worn  out  with  the  long  contest  the  spread 
of  the  disease  is  no  longer  opposed  by  the  tuberculous 
patient,  he  may  be  susceptible  to  outside  infection,  but  then 
the  fact  is  immaterial  —  the  fatal  issue  will  hardly  thereby 
be  hastened.  The  infection  with  tuberculosis  differs  again 
from  vaccination  against  smallpox  in  the  important  par- 
ticular that  being  a  continuing  infection,  it  is  always  ready 
to  take  advantage  of  a  temporary  weakness  of  its  opponent 
to  spread  more  widely,  perhaps  fatally.  The  fact  that  the 
individual  who  is  immunized  against  tuberculosis  may, 
nevertheless,  die  of  his  disease  leads  many  to  deny  the 
existence  of  an  immunity  in  tuberculosis.  But  the  fact 
that  resistance  may  be  overcome  is  not  a  proof  that  it  does 
not  exist.  It  has  been  shown  that  tubercle  bacilli  circu- 
late in  the  blood  from  time  to  time  in  many,  if  not  in  all, 
cases  of  tuberculosis,  but  without,  as  a  rule,  infecting  parts 
away  from  the  existing  lesions.  There  is,  then,  what  may 
be  called  an  immunity  against  circulating  tubercle  bacilli  in 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  71 

all  cases  of  chronic  tuberculous  infection  until  a  complete 
breakdown  occurs,  as  shortly  before  death  from  tubercu- 
losis. Thus  only  is  that  localization  of  the  tuberculous 
process  possible  which  is  so  important  a  feature  in  the  more 
chronic  types  of  tuberculosis.  But  it  is  quite  conceivable 
that  the  patient  may  be  able  to  restrain  the  development  of 
new  foci  at  a  distance,  but  not  capable  of  preventing  the 
growth  of  large  existing  lesions.  That  is,  the  immunity 
may  be  sufficient  to  overcome  scattered  foes,  but  not  to  cope 
with  large  numbers  of  the  enemy  when  aggregated. 

Or,  to  put  it  in  still  another  way,  the  immunity  of  tissues 
at  a  distance  may  be  perfect  against  invading  tubercle 
bacilli,  but  tissues  more  or  less  surrounded  by  colonies  of 
tubercle  bacilli  and  by  accumulations  of  their  poisonous 
products  may  in  time  be  hopelessly  poisoned.  At  a  dis- 
tance from  the  lesion  antibodies  predominate;  about  the 
lesion  they  are  outnumbered. 

The  tubercle  bacilli  that  enter  the  blood  are  dispersed 
throughout  the  body  —  acute  miliary  tuberculosis  is  hema- 
togenous. On  the  other  hand,  the  lymphatic  system  is  the 
collecting  agency  for  bacteria  from  the  blood  as  well  as  for 
those  that  enter  the  body  from  without.  Moreover  the 
sluggish  flow  in  the  lymph  vessels  favors  the  accumulation 
of  the  poisonous  products  of  the  tubercle  bacillus.  Hence 
we  find  that  the  extensions  in  localized  tuberculosis  are 
usually  lymphogenous  and,  at  first  at  least,  develop  in  the 
vicinity  of  large  collections  of  tuberculous  poison  —  either 
large  old  tuberculous  foci  of  the  parenchyma,  or  caseated 
glands. 

It  follows,  then,  that  the  prognosis  in  tuberculosis  will  be 
the  more  unfavorable  the  greater  the  amount  of  tubercu- 
lous tissue  present  in  the  given  case.  A  mature  immunity 
will  as  a  rule  be  high  and  easily  maintained  if  the  tubercu- 


72  EPIDEMIOLOGY   OF  TUBERCULOSIS 

lous  foci  present  are  small  in  size  and  few  in  number,  but 
exceptionally  immunity  appears  to  be  totally  lost  from  un- 
known causes  though  the  tuberculous  lesions  are  small. 

We  recognize  two  degrees  of  immunity  in  tuberculosis: 
First,  immunity  against  the  tubercle  bacillus  —  tuberculous 
bacteriemia  does  not  create  new  foci.  Second,  immunity 
against  tubercle  bacilli  and  accumulations  of  their  poison- 
ous products,  an  immunity  which  is  maintained  with  diffi- 
culty in  the  presence  of  large  tuberculous  foci. 

Primary  tuberculosis  is  seen  with  us  practically  only  in 
young  children.  It  was  formerly  held  that  infection  at  this 
age  is  always  fatal,  but  this  is  far  from  being  true.  As 
has  been  shown  by  tuberculin  reactions,  a  considerable  per- 
centage of  young  children  go  on  to  develop  an  immunity 
as  the  result  of  the  early  inoculation  and  may  never 
exhibit  any  manifestations  of  clinically  apparent  tubercu- 
losis. In  such  cases  we  may  infer  from  analogy  with  the 
results  of  experimentation  with  animals  that  the  dosage  of 
the  infectious  agent  has  been  small  and  that  the  native 
resistance  has  been  sufficient  to  prevent  early  and  rapid 
multiplication  of  the  infecting  bacilli.  As  a  result  of  the 
almost  instantaneous  reaction  to  the  new  poison,  the  lymph- 
glands  as  well  as  the  other  tissues  acquire  at  first  an  in- 
creased activity  which  in  time  becomes  an  insensitivenesa 
to  tuberculous  infection  whether  exogenous  or  endogenous, 
so  that  reinfections  produce,  according  to  the  dosage,  either 
no  visible  lesion  or  one  that  heals.  The  fundamental  dis- 
tinction between  primary  and  secondary  tuberculosis  is 
that  in  the  latter  the  glands  do  not  swell.  The  child  which 
has  received  a  tuberculous  infection  of  the  nature  of  a 
vaccination  against  the  disease  never  has  any  marked 
swelling  of  newly  involved  lymph-glands  whatever  its  sub- 
sequent history  as  respects  tuberculosis  may  be. 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  73 

If  the  initial  dosage  is  larger,  the  tuberculosis  of  the 
glands  advances  more  rapidly  for  a  time  than  the  immuni- 
zation of  the  tissues,  with  the  result  that  the  lymph-glands 
swell  to  a  certain  extent  and  become  more  or  less  caseous. 
There  is  a  great  variety  of  possibilities  as  respects  the  ex- 
tension through  the  lymphatic  system  of  this  type  of  tuber- 
culosis, as  Harbitz1  has  shown.  The  disease  is  more  severe 
than  in  the  first  type,  the  caseations  present  are  a  constant 
menace  and  there  may  be  involvement  of  various  viscera, 
bones  and  joints  according  to  the  location  of  the  most  seri- 
ously affected  lymph-glands,  but  still  the  course  of  the  dis- 
ease is  chronic  and  it  is  not  necessarily  incompatible  with  a 
very  considerable  duration  of  life. 

If  the  initial  dose  is  still  larger,  or  if  native  resistance  is 
low,  or  if  both  unfavorable  factors  are  present,  the  glands 
become  greatly  swollen,  caseate  and  suppurate  with  early 
overflow  upon  the  viscera,  resulting  in  acute  and  fatal 
disease. 

As  respects  the  implication  of  the  lymph-gland  system 
we  may  distinguish  three  types  of  tuberculosis :  First,  the 
small  infection  in  which  there  is  no  considerable  swelling 
and  only  minimal  caseation  of  iymph-glands  —  the  infec- 
tion of  immunization. 

Second,  the  type  of  chronic  generalization  in  the  lymph- 
gland  system,  the  tuberculosis  which  is  sometimes  called 
scrofula,  in  which  there  is  more  or  less  extensive  caseation 
of  lymph-glands  —  the  infection  of  imperfect  immunization. 

Third,  acute  generalization  of  tuberculosis  in  the  lymph- 
gland  system  in  which  there  is  no  immunity. 

In  the  first  type  there  is  either  no  manifest  tuberculosis 
at  all,  or  if  manifest  disease  declares  itself  the  form  will  be 
that  of  chronic  phthisis.     In  the  second  the  disease  may 

1Haufigkeit  u.  Legalisation  d.  Tuberkulose,  etc.,  Christiana,  1905. 


74  EPIDEMIOLOGY  OF  TUBERCULOSIS 

manifest  itself  in  a  variety  of  forms  in  childhood  —  bone 
and  joint  tuberculosis  and  the  like  —  but  in  many  cases  the 
termination  is  in  chronic  pulmonary  tuberculosis  in  adult 
life.  It  is  particularly  important  to  note  that  though  the 
first  and  second  types  are  those  of  chronic  disease  and  are 
spoken  of  as  later  forms  of  tuberculosis,  yet  the  fact  that 
they  are  later  in  appearance  and  chronic  in  course  does 
not  prove  that  the  primary  infection  was  of  later  date  than 
one  which  has  resulted  in  actual  fatal  disease.  These  two 
types,  in  other  words,  are  to  be  regarded  as  manifestations 
of  the  reaction  of  more  or  less  immunized  organisms  to  an 
enemy  which  they  are  not  able  to  subdue  without  a  strug- 
gle, the  ability  to  develop  a  resistance  being  rendered  pos- 
sible by  the  fact  that  the  original  infection  was  not  an  over- 
whelming one. 

The  fate  of  the  individual  as  respects  tuberculosis  de- 
pends therefore  throughout  life  very  largely  upon  the 
nature  of  his  original  infection. 

The  feature  which  distinguishes  primary  tuberculosis 
from  the  later  forms  is  that  as  a  manifest  organic  disease 
which  has  passed  beyond  the  limits  of  the  lymph-gland 
system  it  is  invariably  fatal.  The  alternative  for  the  young 
child  is  immunization  or  death  from  generalized  tubercu- 
losis. 

The  same  is  true  of  primary  tuberculosis  in  the  adult. 
He  also  may  become  immunized  by  a  small  infection,  but  if 
manifest  tuberculosis  declares  itself  within  a  brief  period 
after  infection  he  will  quickly  die. 

Fraenkel1  states  that  the  peculiarities  of  its  course  justify 
the  consideration  of  the  tuberculosis  of  early  childhood  (to 
the  5th  to  7th  year  of  life)  separately  from  that  of  later 
youth.     He    distinguishes    two    types:      (1)     Generalized 

'Pathologie  und  Therapie  der  Lungenkrankheiten,  p.  761. 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  75 

chronic  tuberculosis,  sometimes  afebrile  or  with  remitting 
or  hectic  fever.  Here  there  is  an  increasing  cachexia-like 
atrophy,  almost  constant  swelling  of  spleen  and  liver, 
moderate  swelling  of  numerous  lymph-glands,  cervical,  occi- 
pital and  inguinal.  Tuberculosis  meningitis  is  often  the 
only  sign  of  tuberculosis  except  the  emaciation.  Yet  at 
autopsy  almost  always  extensive  lesions  of  the  most  various 
organs  (especially,  besides  the  lungs,  the  liver,  spleen,  and 
bronchial  and  abdominal  lymph-glands)  are  found,  some- 
times as  large  conglomerate  tubercles,  sometimes  as  miliary 
foci.  (2)  Acute  and  subacute  miliary  tuberculosis.  This 
is  generalized  like  the  other  form  but  the  sudden  irruption 
of  numerous  tubercle  bacilli  into  the  circulation  and  the 
development  of  massive  nodules  in  the  internal  organs  pro- 
duces a  more  stormy  course.  Fever  is  rarely  absent.  In 
some  cases  general  symptoms  predominate.  There  is  a 
typhoid  condition  with  great  prostration,  swelling  of  abdo- 
men, delirium,  dyspnoea,  cyanosis  and  death  in  one  to  three 
weeks.  Tropical  writers  describe  cases  with  similar  course 
among  the  adult  natives.  Perhaps  the  most  vivid  descrip- 
tion is  that  of  Woods  Hutchinson,  who  writes  of  tuberculo- 
sis as  it  affects  the  Indian  population  of  the  Pacific  north- 
west and  describes  what  is  evidently  primary  tuberculosis. 
He  says  :x 

"  I  could  hardly  believe  my  ears  when  some  of  the  agency 
physicians  assured  me  that  they  had  seen  adult  braves  die 
in  three  weeks  of  tuberculosis.  All  united  in  the  statement 
that  the  disease  usually  ran  its  course  in  about  nine  months 
in  adults,  seldom  extending  beyond  a  year,  and,  taking 
children  into  consideration,  the  average  duration  of  the  dis- 
ease from  start  to  fatal  termination  would  not  average 
much  more  than  four  to  six  months.     Moreover  those  who 

1N.  Y.  Med.  Jour.     Vol.  86,  1907,  pp.  624  and  671. 


76  EPIDEMIOLOGY  OF  TUBERCULOSIS 

went  into  details  described  a  new  and  curiously  uniform 
type  of  the  disease,  beginning  with  fatigue,  shortness  of 
breath,  pallor  or  blueness  of  lips,  rapid  pulse  and  fre- 
quently subnormal  temperature,  with  exceedingly  rapid 
consolidation  of  the  lungs,  beginning  with  the  apices.  The 
patients  would  lose  weight  with  frightful  rapidity,  fall  into 
a  muttering  delirium  and  die  of  heart  failure,  much  as  in 
septic  pneumonia  or  in  typhoid.  Nearly  all  of  them  also 
had  been  struck  with  the  large  amount  of  glandular  tuber- 
culosis both  in  the  fatal  cases  and  in  the  survivors." 

Tuberculosis  changes  found  at  autopsy  are  of  three  gen- 
eral types :  the  tuberculosis  of  the  more  or  less  well-immun- 
ized individual,  the  tuberculosis  of  the  imperfectly  immun- 
ized individual  and  primary  tuberculosis  in  which  there  is 
little  or  no  immunity. 

1.  a)  Tuberculosis  the  cause  or  the  accessory  cause  of 
death.  The  more  or  less  well-immunized  subject  presents 
the  characteristics  of  chronic  phthisis  as  it  is  found  in  the 
temperate  zones  —  a  slowly  progressive  disease  long  lim- 
ited to  the  lungs  and  with  a  marked  tendency  to  localiza- 
tion and  repair,  characterized  by  the  presence  of  abundant 
firm  fibrous  tissue,  especially  in  the  upper  lobes  and  about 
the  hilus,  with  or  without  cavities.  Early  extensions  are 
usually  in  the  form  of  a  few  large  conglomerate  tubercles, 
later  extensions  appearing  as  wider  disseminations  of 
more  numerous  and  smaller  tubercles,  peribronchial 
and  bronchial  tuberculosis,  or  as  hematogenous  mili- 
ary tubercles.  Or  the  later  tuberculosis  may  mani- 
fest itself  as  an  invasion  of  the  parenchyma  by 
lobar  pneumonia  or  broncho-pneumonia,  terminating 
in  extensive  caseations.  When  death  occurs  from  tu- 
berculosis, the  immunity  disappears  as  a  rule  before 
death,  with  the  result  that  there  is  a  general  dissemination 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  77 

of  tubercle  bacilli  throughout  the  body.  If  life  is  suffi- 
ciently prolonged,  these  may  lead  to  the  formation  of 
numerous  macroscopic  miliary  tubercles.  More  usually, 
however,  the  foci  are  determinable  only  by  the  microscope. 
Large  conglomerate  tubercles  are  rarely  seen  in  the  liver 
and  spleen,  but  smaller  foci  of  hematogenous  origin,  often 
fibrous  or  calcified,  may  be  found  in  spleen,  kidney,  and, 
more  rarely,  in  the  liver.  Microscopic  tubercle  of  liver 
and  spleen  are,  however,  usually  present  as  the  result  of  the 
antemortem  invasion  of  tubercle  bacilli. 

However  completely  the  subject  may  have  lost  his  origi- 
nal immunity  before  death,  the  fact  that  it  has  existed  is 
shown  by  the  presence  of  fibrous  tissue  and  the  amount  of 
this  fibrous  tissue  constitutes  the  best  evidence  of  the 
degree  of  resistance  that  has  been  attained  during  the 
course  of  the  disease.  Cavity  has  been  regarded  as  a  sign 
of  immunity  but  this  is  true  only  of  the  cavity  which  is 
encapsulated  with  fibrous  tissue.  It  is  not  the  presence  of 
a  large  broken-down  focus  which  constitutes  a  sign  of  im- 
munity but  the  thick  fibrous  walls  by  which  said  focus  has 
been  enclosed.  A  further  evidence  of  immunity  is  the  ab- 
sence of  much  enlarged  lymph-glands  in  the  thorax  and 
elsewhere.  A  primary  tuberculous  focus  is  regularly  ac- 
companied by  a  well-marked  adenitis  of  the  regional  lymph- 
glands.  The  most  usual  extra-thoracic  extensions  of  tuber- 
culosis in  the  fairly  immunized  subject  are  as  tuberculous 
laryngitis  and  enteritis.  Characteristic  of  the  secondary 
nature  of  these  complications  is  the  absence  of  swelling  of 
regional  glands,  or  if  the  glands  swell,  as  is  more  often  the 
case  in  tuberculosis  of  the  intestine  than  in  that  of  the 
larynx,  the  swelling  is  slight  in  comparision  with  that  seen 
in  primary  tuberculosis. 

b)  Tuberculosis  is  discovered  after  death  from  another 


78  EPIDEMIOLOGY  OF  TUBERCULOSIS 

cause.  Fibrous  or  calcined  tubercle,  adhesions  of  the 
pleura,  localized  fibrous  thickenings  and  small,  dry  cavities 
of  the  apex  or  upper  part  of  the  upper  lobe  speak  for  the 
existence  of  a  healed  tuberculosis,  and  hence  of  an  immu> 
nity.  Other  evidence  is  furnished  by  small  calcified  or 
fibrous  foci  of  the  lung  parenchyma,  and  fibrous  and  indu- 
rated peribronchial  and  hilus  lymphatic  glands.  Large 
caseated  glands  are  not  found  in  this  type  of  tuberculosis. 
In  the  study  of  the  epidemiology  of  tropical  tuberculosis 
no  opportunity  should  be  lost  to  search  for  these  evidences 
of  an  early  tuberculous  infection.  They  are  discovered  if 
persistently  sought  for  in  the  large  majority  of  the  autop- 
sies of  civilized  man.  The  percentage  in  which  they  are  to 
be  found  in  the  tropics  is  important  evidence  of  the  degree 
of  tuberculization  of  the  community.  In  eight  deaths  from 
tuberculosis  of  negroes  of  Kamerun,  Lohlein1  found  evi- 
dences of  old,  more  or  less  cured  tuberculous  infection  in 
but  one.  Here  the  bronchial  glands  contained  some  old 
calcified  nodules  and  there  was  extensive  adhesive  pleurisy. 
But  of  fifteen  adult  Hottentots,  four  (26.6  per  cent.) 
showed  old  processes  of  slight  extent  in  lungs  and  bronchial 
glands.  McCarthy2  reports  that  in  over  six  hundred  autop- 
sies at  Panama  of  West  Indian  negroes,  he  observed  but 
one  healed  tuberculosis  where  the  focus  was  of  any  con- 
siderable size,  but  saw  a  few  cases  among  American 
negroes  where  cicatricial  tissue  had  replaced  tuberculous* 
foci  to  a  considerable  extent.  In  most  cases,  among  the 
West  Indians,  the  tuberculosis  of  the  lungs  took  the  form 
of  caseous  bronchopneumonia,  with  rarely  any  attempt  at 
repair.  Among  the  natives  of  Batavia  benign  types  are 
frequent  and  at  autopsy  old  tuberculous  foci  are  found  in 

•Archiv  f.  Sohiffs-u.  Tropenhyg.     Vol.  16,  1912,  Beiheft  9,  p.  18. 
aLoc.  cit. 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  79 

the  lungs  in  about  one-half  of  the  cases  in  which  tuberculo- 
sis was  not  the  cause  of  death.  But  in  the  country  dis- 
tricts of  Java,  where  tuberculosis  is  rare  but  very  fatal, 
evidences  of  previous  infection  are  rarely  seen  after  death. 
2.  The  tuberculosis  of  the  imperfectly  immunized  indi- 
vidual. The  relative  absence  of  immunity  is  shown  by 
chronic  enlargement  of  lymph-glands.  When  the  initial 
infection  is  small  and  the  health  of  the  subject  is  good,  the 
processes  of  immunization  advance  so  rapidly  that  the 
lymph-glands  become  insensitive  to  the  tuberculous  poison 
at  an  early  period,  as  do  the  other  tissues  of  the  body,  hence 
they  never  swell  so  as  to  become  clinically  recognizable. 
Such  swelling  as  may  be  found  at  autopsy,  though  repre- 
senting a  considerable  increase  over  the  very  small  normal 
size  of  the  glands,  is  not  large  in  the  clinical  sense.  The 
glands  are  not  caseated  (though  occasionally  miliary 
tubercles  are  seen  in  them  as  the  result  of  the  ante-mortem 
bacteremia)  and  are  indurated  from  fibrous  changes. 
Whereas  in  the  class  now  under  consideration,  whether 
because  the  initial  infection  has  been  too  large,  because  it 
has  been  often  repeated  before  immunization  has  de- 
veloped, or  because  the  health  of  the  individual  has 
not  sufficed  to  restrain  multiplication  of  the  bacilli, 
the  glands  are  more  seriously  infected,  swell  consider- 
ably and  become  caseous.  One  group  of  glands,  as  the 
cervical  or  the  hilus  glands,  may  alone  be  affected  or  the 
chief  gland  groups  of  the  body  cavities  may  all  be  involved 
to  a  greater  or  less  extent.  Besides  the  cervical  and  thora- 
cic glands,  the  most  important  groups  are  the  portal  glands, 
the  glands  about  the  head  of  the  pancreas,  the  aortic  glands 
at  the  hilus  of  the  kidney,  the  mesenteric  glands  and  the 
iliac  and  inguinal  glands.  A  massive  primary  infection 
soon  leaves  the  glandular  system  to  invade  the  parenchyma 


80  EPIDEMIOLOGY  OF  TUBERCULOSIS 

of  neighboring  organs,  as  when  tuberculosis  of  the  tracheo- 
bronchial glands  extends  to  become  pulmonary  tuberculo- 
sis. But  in  some  instances  the  disease,  having  originally 
a  slower  rate  of  progression,  remains  long  confined  to  the 
lymphatic  system  and  may  in  the  end  attack  by  direct 
lymphogenous  extension  any  of  the  organs,  the  lungs 
chiefly,  but  also  kidneys,  intestine,  peritoneum,  genitals, 
etc.  Tuberculosis  of  the  skin  (tuberculides),  eye,  bones 
and  joints  is  characteristic  of  this  type,  the  joints  and  the 
spinal  vertebrae  being  especially  exposed  to  attack  by  direct 
extension  on  account  of  the  proximity  of  important  glands. 
In  the  more  chronic  forms  of  this  type  there  is  usually  some 
evidence  of  proliferation  of  fibrous  tissue. 

3.  Primary  tuberculosis.  As  it  appears  in  the  young 
child,  a  massive  tuberculous  infection  results  in  a  general- 
ized tuberculosis  very  different  from  the  chronic  lung  dis- 
ease of  the  adult.  "  The  course  of  tuberculosis,"  says 
Heineman  of  the  Javanese  laborers  in  Sumatra,  "  is,  unlike 
that  of  Europe,  a  very  severe  acute  or  subacute  disease 
which  in  its  tendency  to  generalization  resembles  that  of 
the  earliest  childhood  in  Europe  'V  In  fact  the  experience 
in  the  tropics  with  adults  shows  that  the  peculiarities  of 
the  tuberculosis  of  the  earliest  years,  as  we  know  it,  are  not 
due  to  the  age  of  the  child  but  to  the  absence  of  an  immu- 
nity from  previous  infection.  There  is  a  great  variety  of 
manifestations  of  primary  tuberculosis.  Some  forms  found 
even  under  civilized  conditions,  that  give  little  evidence  of 
resistance,  have  probably  been  previously  exposed  to  infec- 
tion and  are  not,  speaking  strictly,  primary  cases.  This  class 
shades  into  the  preceding,  from  which  it  is  distinguished  by 
its  acute  course  and  early  onset  after  infection.  The  most 
characteristic  feature  of  primary  tuberculosis  is  general 

1  Hamburgische  Med.  Ueberseehefte.    Vol.  1,  1914,  p.  34. 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  81 

implication  of  the  lymph-glands,  not  in  a  chronic  form  as 
in  the  imperfectly  immunized,  but  manifesting  itself  often 
as  great  packets  of  enormously  enlarged  caseated  and  sup- 
purating glands.  Some  observers  report  large  caseous 
masses  in  nearly  every  case  autopsied.1  Mouchet2  in  the 
Belgian  Congo  in  31  autopsies  saw  12  cases  of  miliary 
tuberculosis.  In  all  of  these  with  one  exception  there  were 
great  caseated  glandular  foci  most  frequent  in  the  hilus  or 
mediastinum,  but  also  found  in  the  mesentery  or  in  front 
of  the  spine.  The  lungs  are  very  frequently  involved,  pre- 
dominatingly as  caseous  bronchopneumonia  or  caseous 
lobar  pneumonia.  In  fifty  per  cent,  of  cases  of  pulmonary 
tuberculosis,  Mouchet  saw  a  yellowish  oedematous  infiltra- 
tion of  the  lung,  "  gelatinous  "  pneumonia.  The  lungs  may 
also  be  filled  with  miliary  tubercles,  usually  as  a  part  of 
generalized  miliary  tuberculosis.  A  significant  fact  is 
that  there  is  no  evidence  of  attempt  at  repair  by  the  pro- 
liferation of  fibrous  tissue. 

Another  characteristic  manifestation  is  the  primary  in- 
volvement of  serous  membrances.  Pleura,  pericardium  and 
peritoneum  may  be  implicated  in  the  same  subject  —  the 
disease  is  a  tuberculous  serositis.  Tuberculosis  of  serous 
membranes  may  present  itself  as  disseminated  miliary 
tubercles,  or  as  massive  caseations,  or  as  fungoid  tubercu- 
lous granulations  making  mushroom-like  growths.  Pleural 
adhesions  are  often  absent  and  rarely  extensive.  Effusion 
occurs  in  practically  all  cases  in  which  the  pleura  is  not 
adherent.  Sometimes  in  place  of  fibrinous  exudate  the 
pleura  is  coated  with  a  voluminous  lardaceous  substance. 
The  liver  and  spleen  may  be  attacked  by  tuberculosis  in  the 

1 A  district  surgeon  says  of  Natal  and  Zululand:  "There  is  an  exceed- 
ing prevalence  of  large  glandular  masses".  So.  African  Med.  Rec,  Vol.  13, 
1915,  p.  139. 

'Bull.  Soc.  Path.  Exot.     Vol.  6,  1913,  p.  11. 


82  EPIDEMIOLOGY   OF   TUBERCULOSIS 

form  of  perihepatitis  and  perisplenitis,  but  large  conglom- 
erate tubercles  are  found  in  them  as  well  as  in  the  kidney. 
Very  characteristic  of  primary  tuberculosis  are  caseous 
tubercles  of  the  myocardium  and  the  pericardium.  In  452 
autopsies  of  West  Indian  negroes  in  the  Panama  Canal 
Zone  Clark1  saw  large  caseous  nodules  of  the  myocardium 
15  times,  tuberculous  mural  endocarditis  6  times  and  tuber- 
culous pericarditis  62  times.  He  had  several  cases  in  which 
the  only  extensive  focus  outside  of  the  glands  was  in  the 
heart.  He  also  reports  tuberculosis  of  the  spleen  263 
times,  of  the  liver  238  times  and  of  the  kidney  193  times  in 
the  same  group.  Intestinal  tuberculosis  differs  from  the 
familiar  type  by  the  presence  of  enormously  enlarged  case- 
ous mesenteric  glands.  The  intestinal  ulcers  may  be  more 
acute,  their  bases  may  be  engorged  with  blood. 

Although  much  in  the  above  description  strongly  sug- 
gests bovine  tuberculosis,  it  is  certain  that  little  or  no  in- 
fection from  cattle  occurs  in  the  tropics.  Milk  does  not,  as 
a  rule,  constitute  a  part  of  the  food  of  the  native  and  in- 
fants are  usually  suckled  by  their  mothers. 

Often  cases  of  primary  tuberculosis  are  found  associated 
with  others  that  furnish  evidence  of  a  higher  resistance. 
The  mixed  population  of  a  large  city  will  never  be  entirely 
composed  either  of  highly  immunized  nor  of  unprotected 
individuals. 

The  experience  of  Westenhoeffer2  in  Chile,  and  of  Deycke3 
in  Turkey  are  the  more  valuable  because  not  having  been 
gathered  in  the  tropics  it  illustrates  the  fact  that  the  pecu- 
liarities of  tropical  tuberculosis  are  not  due  to  the  geo- 
graphical location  but  to  the  absence  of  protection  from 
previous  infection. 

'Am.  Jour.  Trop.  Dis.  and  Prev.  Med.     Vol.  3,  1915-1916,  p.  331. 

*Berl.  Klin.  Wochenschr.     1911,  p.  2063. 

*  Beitr.  z.  Klinik  d.  Tub.    Fourth  Supplementary  Vol.,  p.  60. 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  83 

Westenhoeffer  states  that  of  48  cases  of  pulmonary 
tuberculosis  which  had  led  to  death  there  were  only  28 
which  permitted  the  assumption  of  a  chronic  course  and 
even  in  these  there  was  in  general  an  absence  of  a  tendency 
to  connective  tissue  formation  and  cavitation.  On  the 
other  hand  17  cases  did  not  give  the  picture  of  chronic 
tuberculosis.  The  majority  were  extensive  confluent, 
cheesy  pneumonias,  in  some  cases  involving  entire  lobes. 
In  many  of  these  cases  the  pleura  was  destitute  of  old 
fibrous  adhesions  and  thickenings  being  simply  clouded 
and  in  spots  covered  with  a  thin  fibrinous  deposit.  The 
bronchial  lymph-glands  in  the  majority  of  cases  showed  a 
succulent  swelling  with  fresh  caseations,  only  rarely  indu- 
rative conditions  or  old  caseations.  In  at  least  one-third  of 
Westenhoeffer's  cases  the  disease  was  quite  acute,  as  would 
be  anticipated,  he  says,  when  patients  are  attacked  by 
tuberculosis  who  are  not  in  the  least  immunized  by  prece- 
dent mild  infections.  The  high  number  of  secondary  intes- 
tinal affections  (more  than  one-half  of  the  cases)  as  well 
as  the  other  extensions  of  tuberculosis  and  the  relatively 
high  number  of  conglomerate  tubercles  in  adults  favor  the 
same  view.  Tuberculosis  in  Chile  appears  preponderat- 
ingly  as  an  acute  infectious  disease  which  destroys  as  many 
lives  proportionately  to  population  as  in  Europe,  but  at  the 
most,  one-half  as  many  proportionately  are  sick  with  it. 

Deycke,  at  a  military  hospital  and  medical  school  in  Con- 
stantinople, to  which  came  students  from  the  entire  Turk- 
ish Empire,  had  a  similar  experience.     He  says : 

"  The  picture  of  ulcerating  phthisis  with  its  beginning  in 
the  apices  and  the  slow  extension  of  the  process  to  the  other 
parts  of  the  lungs,  its  chronic  course  with  its  temporary 
improvements  and  deteriorations,  the  strongly  marked 
tendency  to  mixed  infections,  to  cavernous  breaking  down 


84  EPIDEMIOLOGY  OF  TUBERCULOSIS 

of  the  tissues  —  all  this  is  seen  not  rarely  in  Turkey,  but  it 
does  not  dominate  the  pathology  of  tuberculosis  in  the  same 
degree  as  with  us.  Here  in  this  hospital,  going  from  bed 
to  bed,  I  see  the  monotonous  picture  of  chronic  pulmonary 
tuberculosis  which  it  is  not  necessary  to  describe.  In  Tur- 
key the  picture  was  much  more  changeful.  Predominating 
were  the  dry  forms  of  pulmonary  tuberculosis,  i.  e.,  dissem- 
inated miliary  tuberculosis,  cheesy  peribronchitis  and 
bronchial  pnuemonia  and  cheesy  lobar  pneumonia.  The 
tendency  to  breaking  down  was  relatively  slight,  partly 
perhaps  for  the  reason  that  oftener  than  with  us  one  had 
to  do  with  true  tuberculosis  without  mixed  infection,  hence 
clinically  dry  sounds,  bronchial  breathing,  dullness,  etc., 
were  more  frequent  than  moist  and  resonant  rales  and  am- 
phoric breathing  and  the  like  and  not  infrequently  the 
physical  findings  were  greatly  disproportionate  to  the  bad 
general  condition  of  the  patient  and  the  extent  of  the 
lesions  as  found  later  at  autopsy.  To  be  able  to  demon- 
strate true  clinical  cavity  signs  was  often  impracticable  in 
spite  of  a  large  number  of  tuberculous  patients.  It  was 
comparatively  rare  that  I  could  demonstrate  elastic  fibres 
in  the  sputum,  though  I  searched  for  them  often  enough, 
but  from  this  it  must  not  be  supposed  that  tuberculosis  of 
the  lungs  in  the  absence  of  the  tendency  to  breaking  down 
ran  a  more  benign  course  than  with  us.  Quite  the  con- 
trary. I  very  soon  gained  the  impression  that  the  disease 
extended  in  general  more  rapidly  than  with  us  and  not 
rarely  appeared  under  the  form  of  an  acute  or  subacute 
infectious  disease  with  high  fever  and  rapid  loss  of 
strength. 

"  A  form  of  tuberculosis  which  appears  relatively  often 
in  Turkey  is  primary  tuberculosis  of  the  serous  membranes. 
Not  only  pleurisy  but  also  tuberculous  peritonitis  are  fre- 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  85 

quent  diseases  in  Turkey,  not  in  the  form  of  secondary  in- 
fections of  pleura  or  peritoneum  but  as  primary  diseases 
without  implication  of  the  lung  or  of  the  intestine.  Among 
such  cases  also  the  number  of  so-called  dry  forms  in  rela- 
tively large.  One  sees  with  unusual  frequency  nodular 
tuberculosis  of  the  pleura  and  of  the  peritoneum,  the  two 
being  usually  associated  with  one  another  so  that  one  would 
have  to  speak  of  a  polyserositis  tuberculosa  especially  as  the 
pericardium  also  is  frequently  attacked.  One  finds  an  ob- 
literating pleurisy  where  the  former  pleural  cavity  is  re- 
placed by  fibrinous  or  even  fibrous  thickenings  some  centi- 
meters in  thickness,  interspersed  by  great,  flat  caseous 
nodes.  In  the  abdominal  cavity  an  analogous  caseous  peri- 
hepatitis and  perisplenitis  are  almost  constant  findings. 
One  finds  also  very  frequently  a  tumor-like  change  of  the 
great  omentum,  the  latter  being  contracted  longitudinally 
but  at  the  same  time  enormously  thickened  and  projected 
upward  against  the  abdominal  wall  in  such  a  way  that  it  is 
often  accessible  to  palpation  intra-vitam  and  gives  occasion 
the  more  readily  to  diagnostic  errors  because  the  objective 
clinical  signs  of  tuberculosis  may  be  entirely  absent.  The 
section  of  such  omental  tumors  shows  that  they  are  com- 
pletely made  up  of  tuberculous  granulation  tissue  in  which 
large  and  small  cheesy  nodes  are  abundantly  interspersed. 
On  the  peritoneum  one  finds  also  tuberculous  nodes  of  luxu- 
rious growth  like  mushrooms.  Often  the  tissue  of  the 
spleen  is  filled  with  caseous  nodules.  Of  course  the  bron- 
chial and  mesenteric  glands  are  also  seriously  affected,  and 
on  the  other  hand  true  pulmonary  tissue  and  intestine  are 
either  entirely  intact  or  freshly,  that  is,  secondarily  in- 
fected. All  these  cases  have  an  unmistakable  similarity  to 
tuberculosis  of  cattle,  though  of  course  this  resemblance  is 
only  external." 


86  EPIDEMIOLOGY  OF  TUBERCULOSIS 

"  Wieting  observed  the  surprisingly  great  number  of 
tuberculous  diseases  of  the  lymph-glands,  especially  of  the 
cervical  lymph-glands,  so  that  he  inquired  whether  the 
mouth  and  pharynx  do  not  form  the  portals  of  entry  for  the 
tuberculous  virus  much  more  frequently  than  has  hitherto 
been  assumed.    The  following  is  a  quotation  from  Wieting :" 

1  As  a  proof  of  the  great  frequency  of  infection  from 
mouth  or  pharynx,  I  record  the  enormous  number  of  cases 
of  tuberculous  diseases  of  the  cervical  glands.  Of  3256 
cases  in  the  polyclinic,  335  were  of  tuberculous  lymph  adeni- 
tis, almost  exclusively  of  the  neck,  that  is,  over  10  per  cent, 
of  all  cases  treated.  Of  the  total  cases  of  tuberculous  dis- 
eases, numbering  1244,  there  were  of  tuberculous  lymph- 
adenitis of  the  neck  alone  346,  that  is,  31  per  cent.,  and 
these  only  cases  which  came  into  treatment  especially  on 
account  of  the  lymph-gland  affection.  Of  all  the  other 
cases  of  surgical  tuberculosis,  especially  bone  tuberculosis, 
there  were  scarcely  one  in  ten  that  did  not  have  at  the 
same  time  an  affection  of  the  cervical  glands.' 

"  Of  the  bone  and  joint  tuberculosis  in  Turkey,  I  will 
only  mention  that  according  to  Wieting  this  form  was 
present  in  not  less  than  54  per  cent,  of  the  cases  of  surgi- 
cal tuberculosis,  and  in  11.5  per  cent,  of  all  surgical  cases. 
These  are  numbers  that  are  three  to  five  fold  greater  than 
those  which  we  are  accustomed  to  see  in  Germany.  In  the 
controversies  which  have  arisen  as  to  the  portals  of  entry 
of  the  tubercle  bacilli,  it  has  been  often  assumed  that  a 
finding  of  primary  intestinal  tuberculosis  is  equivalent 
with  alimentary  infection  from  cows'  milk.  Our  patho- 
logico-anatomical  material  shows  that  this  is  not  true  for 
Turkey.  Of  66  autopsies  in  tuberculosis,  in  39  cases,  that 
is,  over  43  per  cent.,  the  undoubtedly  oldest  tuberculous 
changes  were  present  in  the  intestinal  tract  or  in  the  ab- 


PATHOLOGY  AND  PATHOLOGICAL  ANATOMY  87 

dominal  cavity.  In  spite  of  this  interesting  and  surpris- 
ing fact,  my  knowledge  of  the  customs  and  modes  of  life  of 
the  Turkish  people  enables  me  to  determine  with  certainty 
that  their  infections  from  foods  derived  from  cattle,  as 
milk,  butter,  cheese  and  meat,  play  no  role  of  importance. 
We  must,  therefore,  still  hold  fast  to  the  idea  that,  in  Tur- 
key also,  transmission  of  tuberculosis  from  man  to  man  is 
of  the  first  importance.  He  who  knows  Oriental  condi- 
tions, the  ignorance  and  carelessness  of  the  people,  the  cus- 
toms as  to  eating,  etc.,  can  hardly  doubt  that  in  Constanti- 
nople all  the  possibilities  are  present  for  an  extensive  dis- 
semination of  tuberculosis  by  direct  contagion.  If  in  Tur- 
key tuberculosis  is  really  transmitted  from  man  to  man, 
that  fact  must  be  made  apparent  in  places  where  numerous 
persons  live  for  a  long  time  crowded  closely  together.  This 
condition  was  fulfilled  in  the  military  schools,  all  of  them 
boarding  schools,  in  which  the  young  scholars,  coming 
mostly  from  the  provinces,  were  crowded  together  in  quite 
insufficient  space,  under  the  worst  possible  hygienic  condi- 
tions, on  account  of  the  constant  overcrowding,  and  were 
obliged  to  eat  and  sleep  together.  These  schools  were 
really  true  breeding  places  of  tuberculosis,  although  the 
scholars  were  originally  usually  healthy  persons. 

"  In  the  old  army  medical  school,  the  scholars  of  which 
were  largely  young  army  surgeons  who  had  passed  their 
examinations  and  were  sent  to  the  hospital  for  a  year's 
additional  medical  instruction,  we  saw  about  10  per  cent, 
infected  with  tuberculosis  every  year,  and  on  further  inves- 
tigation it  regularly  became  apparent  that  this  10  per  cent. 
was  only  a  remnant  of  the  much  greater  number  of  victims 
who  had  been  eliminated  on  account  of  the  disease  during 
the  nine  years'  period  of  schooling.  This  loss  could  also  be 
estimated  as  an  average  of  10  per  cent.,  so  that  in  general 


88  EPIDEMIOLOGY  OF  TUBERCULOSIS 

there  were  at  least  20  per  cent,  of  cases  of  manifest  tuber- 
culous infection  in  every  class.  About  200  soldiers  were 
assigned  to  the  hospital  as  nurses  and  other  employees. 
Of  these,  also  about  10  per  cent,  were  affected  with  tuber- 
culosis. Repeated  examinations,  not  only  on  entering  the 
service  but  during  service,  and  applying  not  only  to  tuber- 
culosis but  also  to  malaria,  lues,  etc.,  gave  us  the  impression 
that  all  these  soldiers  who  originated  in  the  provinces  and 
had  come  to  Constantinople  for  the  first  time,  had  infected 
themselves  there.  There  can  be  no  doubt  that  there  are 
regions  and  zones  in  the  Osman  Empire  which  are  free  of 
tuberculosis.  Aside  from  the  regions  with  little  tubercu- 
losis in  Turkestan  and  from  the  shepherd  population  in 
many  regions  in  Anatolia  who  are  practically  free  of  tuber- 
culosis, I  would  mention  the  lands  in  the  south  with  a  hot 
climate  like  Arabia,  Tunis,  etc.,  the  population  of  which 
away  from  the  coast  is  absolutely  free  of  tuberculosis,  but 
it  is  precisely  these  cases  and  the  negroes  from  Africa, 
Nubia  and  Sudan  who  fall  ill  in  a  frightful  percentage  with 
tuberculosis  in  Constantinople. 

"  I  believe  that  the  stereotyped  picture  of  consumption  is 
formed  under  the  influence  of  a  relative  tuberculous  im- 
munity of  the  civilized  peoples  thoroughly  infected  with 
tuberculosis,  but  that  the  more  virgin  the  soil,  that  is,  the 
less  the  people  have  come  in  contact  with  tuberculosis  and 
are  infected  with  tuberculosis,  the  more  frequently  do  such 
severe  acute  generalized  forms  of  tuberculosis  appear  as 
are  so  frequent  in  Turkey." 


CHAPTER  VII 
DIAGNOSIS,  ESPECIALLY  TUBEBCULIN  DIAGNOSIS 

The  pulmonary  tuberculosis  with  which  we  are  familiar 
as  "  consumption  "  is  characterized  by  three  features ;  ema- 
ciation, cough  and  chronicity.  This  form  of  tuberculosis 
is  also  the  prevailing  type  in  the  tropical  community  in 
which  tuberculosis  has  long  been  endemic.  In  view,  how- 
ever, of  the  probably  comparatively  incomplete  tuberculi- 
zation of  the  population,  one  must  be  prepared  to  encounter 
more  acute  tuberculous  disease,  cases  which  have  com- 
pletely lost  their  perhaps  recently  acquired  and  certainly 
imperfect  immunization  and  also  cases  which  have  never 
acquired  any  immunity  worthy  of  the  name.  In  lands 
where  tuberculosis  is  not  as  yet  widely  disseminated,  the 
acuter  forms  of  tuberculosis  will  be  the  rule  rather  than 
the  exception. 

The  first  question  which  has  to  be  decided  in  the  further 
diagnosis  of  the  tuberculous  case  is:  Are  there  or  are 
there  not  evidences  of  previous  contact  with  tuberculosis, 
in  other  words,  of  a  certain  degree  of  immunity,  which 
foretells  a  probably  chronic  course  in  those  cases  that  are 
seen  in  their  incipiency?  When  the  disease  is  of  some 
standing,  the  presence  of  a  superficially  situated  cavity  of 
the  upper  lobes,  with  its  well-marked  physical  signs, 
broncho-vesicular  breathing,  especially  over  the  upper  parts 
of  the  lung  (which  in  the  relatively  afebrile,  ambulant  case 
usually  indicates  fibrous  changes),  a  chronic  cough  with 
somewhat  abundant  mucopurulent  sputum  are  all  signs  of 
a  chronic  form  of  tuberculosis  usually  of  a  relatively  be- 
nign type.     This  is  not  equivalent  to  saying  that  the  prog- 

89 


90  EPIDEMIOLOGY  OF  TUBERCULOSIS 

nosis  is  necessarily  good.  In  the  individual  case  the  pre- 
viously existing  immunity  may  have  been  altogether  lost 
and  there  is  always  the  possibility  that  a  generalized 
tuberculosis  may  develop,  as  it  were,  out  of  a  clear  sky,  in 
cases  in  which  the  morbid  process  has  seemed  to  have  little 
activity.  In  general,  however,  in  cases  that  show  in  any 
way  a  previous  acquaintance  with  tuberculosis,  the  disease 
will  pursue  a  chronic  course  and  may  offer  some  prospect 
of  arrest  and  even  of  cure.  In  those  difficult  cases  in  which 
there  is  a  question  whether  ill  health  is  to  be  ascribed  to  a 
masked  tuberculosis,  physical  signs  of  pulmonary  involve- 
ment being  obscure  or  absent,  the  probability  that  this  is 
the  correct  explanation  is  greater  the  more  completely 
tuberculized  the  community  and  the  better  the  hygiene  of 
the  patient  —  persons  living  under  bad  hygienic  conditions 
who  have  had  little  opportunity  for  immunization  are  more 
likely  to  develop  acuter  forms  of  tuberculosis,  if  they  fall 
victims  to  the  disease. 

In  acute  pulmonary  tuberculosis  there  may  be  neither 
emaciation  nor  cough.  The  lungs  are  relatively  dry,  the 
accompanying  bronchitis  is  usually  not  a  conspicuous  fea- 
ture. There  may  be  no  expectoration  —  the  African  negro 
with  pneumonia  or  tuberculosis,  according  to  Mouchet, 
does  not  expectorate.  At  the  outset  an  extensive 
broncho-pneumonia  or  a  lobar  pneumonia  may  fur- 
nish the  usual  auscultatory  signs  of  pneumonia,  crep- 
itant and  subcrepitant  rales.  But  this  stage  is  of 
brief  duration.  After  massive  caseation  has  occurred, 
no  rales  are  heard  except  possibly  coarse  and  distant  rales 
from  the  larger  tubes.  So  it  may  come  about  that  the 
lungs  have  undergone  the  most  profound  and  extensive 
changes  without  furnishing  to  the  physician  the  indications 
which  he  has  been  accustomed  to  find  in  chronic  phthisis. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS  91 

Topical  diagnosis  is  correspondingly  difficult  and  depend- 
ence must  be  placed  more  largely  upon  general  signs  and 
symptoms. 

The  acute  generalized  and  acute  pulmonary  miliary 
tuberculosis  of  the  civilized  world  is  secondary  to  an  old 
lesion  in  the  adult  and  is  not  accompanied  consequently  by 
enlargement  of  the  lymph-glands.  On  the  other  hand, 
tuberculosis  of  the  lymph-glands  is  a  conspicuous,  if  not 
predominating  feature  in  primary  tuberculosis  and  enor- 
mous and  acute  enlargement  of  cervical,  more  rarely  also 
of  axillary  and  femoral  glands  may  indicate  the  nature  of 
the  affection.  The  same  criterion  may  be  of  help  in  the 
diagnosis  of  tuberculous  meningitis.  The  fulminating 
forms  of  tuberculosis  require  to  be  distinguished  from  acute 
infectious  diseases  such  as  typhoid  fever. 

The  cutaneous  tuberculin  test  is  of  value  in  diagnosis  if 
the  result  is  a  positive  reaction.  It  is,  however,  likely  to 
be  negative  in  the  class  of  cases  which  most  require  eluci- 
dation. The  reaction  is  also  usually  negative  in  the 
cachexia  of  advanced  disease,  including  tuberculosis,  and  is 
often  absent  or  weakened  in  acute  infectious  diseases. 
Sensitiveness  to  tuberculin  is  one  of  the  evidences  of  the 
reaction  of  the  organism.  An  organism  not  recently  stim- 
ulated by  tuberculous  poison  may  not  react  to  the  dosage 
of  tuberculin  employed.  On  the  other  hand  an  organism 
overwhelmed  by  an  acute  tuberculosis  is  incapable  of  react- 
ing. And  it  would  appear  that  in  disease  of  a  more  chronic 
and  less  severe  type  the  von  Pirquet  reaction  is  often  nega- 
tive in  the  tropics.  Thus,  three  of  the  adult  Hottentots 
tested  by  Zieman1  in  Kamerun  who  reacted  negatively  had 
signs  of  apical  catarrh,  and  in  German  East  Africa  Man- 

1  Centralblatt  f.  Bakt.  lte  Abt,  Originate.     Vol.  70,  p.  118. 


92  EPIDEMIOLOGY   OF  TUBERCULOSIS 

teufel1  found  the  cutaneous  reaction  negative  "  at  the  be- 
ginning "  in  eight  hospital  cases  of  established  tuberculosis 
with  sputum  positive  for  tubercle  bacilli.  Much2  discov- 
ered at  Jerusalem  that  the  fellaheen  coming  from  the  coun- 
try did  not  react  at  all  to  tuberculin,  and  explained  this 
fact  by  supposing  that  they  had  not  come  into  contact  wltli 
tuberculosis.  But  if  the  Arabs  live  for  some  time  in  the 
cities  they  acquire  a  certain  not  high  capacity  for  reaction. 
Yet  this  reactivity  points  rather  to  an  inactive  than  to  an 
active  tuberculosis,  for  it  is  a  remarkable  fact  that  cases  of 
active  tuberculosis  among  the  Arabs,  not  cases  with 
cachexia  but  comparatively  slight  cases  of  gland  and  bone 
tuberculosis,  were  found  to  have  either  no  reaction  at  all 
or  a  slight  and  delayed  reaction  to  the  cutaneous  tuberculin 
test.  Experiments  by  means  of  the  complement  binding 
reaction  with  his  partial  antigens  showed  Much  that  these 
cases  had  a  humoral,  though  apparently  not  a  cellular  im- 
munity, all  of  the  partial  antigens  being  present  in  their 
blood.  As  for  pulmonary  tuberculosis  of  the  Yemenites 
and  Arabs,  this,  too,  Much  says,  is  of  a  different  type  from 
that  of  the  European,  cases  which  lead  quickly  to  death  in 
which  almost  nothing  is  to  be  found  clinically,  neither  old 
foci  nor  glands  nor  physical  signs  over  the  affected  lung. 
Even  fever  may  be  absent.  As  might  be  expected,  these 
cases  do  not  react  to  tuberculin.  Much  ascribes  the  lacking 
reactivity  of  those  of  the  Arabs  who  have  comparatively 
slight  tuberculosis  to  a  racial  peculiarity.  The  analogy  of 
these  cases,  with  the  negative  African  cases  cited  above,  is, 
however,  evident.  There  is  some  evidence  that  bone  tuber- 
culosis occupies  a  peculiar  position  so  far  as  the  skin-reac- 
tion to  tuberculin  is  concerned.     Thus  Ramsey,  examining 

xArch.  f.  Schiffs-U.  Tropenhyg.    Vol.  18,  1914.  p.  711. 

2  Beitr.  ■/..  Klinik  d.  Tub.     Sixth  Supplementary  Vol.,  p.  25. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS  93 

crippled  children,  reports  that  17  boys  and  11  girls  in  whose 
cases  the  clinical  diagnosis  was  bone  tuberculosis,  had  a 
negative  von  Pirquet  reaction  to  both  human  and  bovine 
tuberculin,  the  tuberculin  being  used  full  strength.1  The 
total  number  of  each  sex  examined  was  58.  Combining 
the  two  sexes,  we  obtain  a  positive  percentage  of  75.86,  a 
low  rate  for  known  tuberculous  cases  tested  with  undiluted 
tuberculin. 

Bitter2  examined  two  series  of  cases  of  tuberculous  sana- 
torium patients  for  the  cutaneous  reaction,  the  one  with 
concentrated,  the  other  with  25  per  cent,  tuberculin.  The 
results  are  shown  in  the  subjoined  table,  to  which  is  added 
the  findings  of  Mirauer,3  with  the  same  tests  in  non-tuber- 
culous patients  in  hospital  and  in  cases  suspected  of  tuber- 
culosis, each  group  having  been  subjected  to  both  tests  at 
the  same  sitting.  Inoculations  were  made  by  both  investi- 
gators with  dilutions  higher  than  25  per  cent.  From  their 
work  it  appears  that  the  percentage  of  positive  reactions 
diminishes  in  proportion  to  the  degree  of  dilution  of  the 
tuberculin. 

That  Mirauer  should  have  obtained  a  lower  percentage  of 
positive  results  is  probably  to  be  explained  rather  by  his 
mode  of  interpretation  than  by  a  difference  in  the  degree  of 
tuberculization  of  his  material,  for  the  percentages  of  Rit- 
ter  agree  much  more  closely  than  his  with  those  usually 
found  in  healthy  men,  and  the  "  suspects  "  have  a  slightly 
lower  positive  reaction  than  the  patients  frankly  classed  as 
non^uberculous.  The  findings  show  the  necessity  of  using 
undiluted  tuberculin  if  it  be  desired  to  ascertain  what  the 
true  degree  of  tuberculization  of  a  given  group  is,  that  is 

'Am.  Jour.  Dis.  Child.     Vol.  10,  1915,  p.  201. 
2  Med.  Krit,  Blatter.     Vol,  1,  1910,  p.  161. 
"Beitr.  z.  Klinik  d.  Tub.     Vol.  18,  p.  51. 


94 


EPIDEMIOLOGY  OF  TUBERCULOSIS 


TABLE  No.  2 

Cutaneous  Tuberculin  Test 
Comparative  results  between  undiluted  and  25  per  cent,  tuberculin 


Stage  (Turban) 
(Ritter) 

Tuberculin  100 
Per  Cent. 

Tuberculin  25 
Per  Cent. 

Num- 
ber of 

Cases 

Num 

ber 

positive 

Per 

cent, 
positive 

Num- 
ber of 
Cases 

Num- 
ber 
positive 

Per 

cent, 
positive 

First 

153 
169 

74 

140 
163 

71 

92. 
96. 
96. 

121 
115 

82 

88 
91 
64 

73. 

Second 

79. 

Third 

78. 

Totals 

396 

374 

94.4 

318 

243 

76.4 

Non-tuberculous 
patients  (Mirauer) 
Tuberculous  sus- 
pects (Mirauer) 

145 
53 

128 

46 

88. 
87. 

145 

53 

115 

41 

79. 
77. 

Grand  Totals 

594 

548 

92.2 

516 

399 

77.3 

to  say,  to  approximate  to  this  as  closely  as  the  nature  of  the 
test  will  permit.  In  fact,  now  that  the  specificity  of  tuber- 
culin reactions  is  admitted,  the  use  of  dilutions  of  tubercu- 
lin in  the  cutaneous  test  has  been  inspired  by  the  hope  that 
with  such  strengths  it  might  be  possible  to  exclude  inactive 
cases  of  tuberculosis.  In  other  words,  dilution  is  expressly 
intended  to  prevent  what  is  especially  needed  in  epidemio- 
logical investigations  —  the  determination  of  the  true  con- 
dition of  the  apparently  healthy  individual  as  respects 
tuberculous  infection.  The  tabulation  now  under  consider- 
ation is  particularly  valuable  to  impress  the  fact  that 
failure  to  react  to  the  cutaneous  test  is  not  by  any  means 
necessarily  due  to  absence  of  tuberculous  infection,  nor  to 
an  exhaustion  of  the  vitality  of  the  patient.     The  average 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS  95 

second  stage  patient  of  Table  2  could  hardly  have  been  far 
advanced  in  tuberculosis,  while  at  the  same  time  there  could 
not  have  been  much  doubt  as  to  the  diagnosis. 

The  same  is  true  of  the  subcutaneous  use  of  tuberculin. 
Of  Bandelier's1  500  sanatorium  patients  173,  or  34.6  per 
cent.,  reacted  to  the  initial  dose  of  1  mg.,  156  or  31.2  per 
cent,  to  5  mg.,  98  or  19.6  per  cent,  to  10  mg.,  and  36  or  7.2 
per  cent,  to  the  second  injection  of  10  mg.,  while  37  or  7.4 
per  cent,  failed  to  react.  Twelve  of  the  37  were  given 
larger  doses,  four  reacted  to  20  mg.  and  six  only  to  50  mg. 
Whether  all  patients  who  react  in  so  slight  a  degree  are  in 
need  of  sanatorium  treatment  is  a  question  that  might  be 
raised  by  the  critical.  Very  possibly,  too,  some  of  the  in- 
sensitiveness  was  due  to  antecedent  tuberculin  treatment, 
although  Ritter  expressly  states  that  he  endeavored  to  ex- 
clude from  his  tests  those  who  were  known  to  have  been 
treated  with  tuberculin.  But  the  point  to  be  especially 
emphasized  is  that  the  patients  subjected  to  these  tests  must 
all  have  been  exposed  to  tuberculous  infection  after  admis- 
sion to  sanatorium  or  hospital,  if  not  before  their  entrance. 
Negative  reactions  therefore  can  not  rightly  be  interpreted 
as  proof  of  absence  of  contact  with  the  tubercle  bacillus. 
Ritter  reports  that  of  eleven  healthy  persons  who  had  been 
much  in  contact  with  tuberculous  patients  and  who  cer- 
tainly must  have  received  infections  only  four  reacted  to 
25  per  cent,  tuberculin.  Perhaps  the  most  striking  in- 
stance of  the  truth  which  it  is  desired  to  convey  is  to  be 
found  in  the  case  of  one  of  his  patients.  This  was  a  young 
man  who  was  hoarse  from  a  laryngeal  lesion  which  had  not 
ulcerated.  There  was  an  incipient  cavity  in  the  right 
upper  lobe  with  slight  catarrh.    The  sputum  contained 

aBeitr.  z.  Klinik  <L  Tub.    Vol.  2,  p.  285. 


96  EPIDEMIOLOGY  OF  TUBERCULOSIS 

tubercle  bacilli.  But  there  was  no  fever,  the  appetite  and 
nutrition  were  excellent  and  the  patient,  a  merchant,  was 
active  in  his  work.  Tuberculin  subcutaneously  adminis- 
tered even  up  to  20  mg.  elicited  no  reaction.  As  Ritter 
says,  certainly  the  absence  of  reaction  in  this  case  did  not 
mean  a  bad  prognosis,  was  not  due,  in  other  words,  to  a 
failure  of  vitality.  While  it  is  generally  believed  that  all 
children  who  are  infected  with  tuberculosis  will  give  a  posi- 
tive reaction  to  tuberculin,  von  Pirquet  recognizes  the  fact 
that  certain  undoubtedly  tuberculous  children  are  negative 
to  the  skin  reaction  "  from  unknown  causes  ".*  Indeed  the 
higher  percentages  of  positive  reaction  obtained  by  Ham- 
burger and  others  with  the  depot  and  stich  reaction  prove 
that  the  skin  test  is  not  sufficiently  delicate  to  detect  all 
cases  of  tuberculous  infection  even  in  children.  For  ex- 
ample, Nothmann  found  that  47.1  per  cent,  of  children  re- 
acted after  one  cutaneous  inoculation,  65.7  per  cent,  after 
two  inoculations,  and  77  per  cent,  when  the  depot  reaction 
was  employed  after  two  negative  skin  reactions.2 

Examination  by  the  cutaneous  tuberculin  test  was  made 
by  Colonel  E.  H.  Bruns,  U.  S.  A.,  in  Germany  of  159  Ameri- 
can soldiers  between  the  ages  of  18  and  30  years,  with  no 
family  history  of  tuberculosis,  for  the  most  part  men  of 
athletic  build.3  The  following  table  gives  the  result  of  the 
tests,  the  men  being  classified  according  to  their  place  of 
residence  before  enlistment  as  city,  town  and  country 
dwellers : 

Unfortunately  the  regiment  to  which  these  men  belonged, 
being  on  the  eve  of  return  to  this  country,  it  was  imprac- 
ticable to  test  farther  the  negative  percentage. 

1  Wien.  Klin.  Wochenschr.     Sept.   19,  1907. 
'Berl.  Klin.  Wochensohr.     Vol.  47,  1910,  p.  381. 

•The    Tuberculosis    Situation    in    the    American    Expeditionary    Forces. 
Unpublished  Report  to  the  Surgeon  General,  U.  S.  A. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS 

TABLE  No.  3 

Cutaneous  Tuberculin  Test  on  159  Healthy  Soldiers 


97 


Class 

43 

s 

+3 

tn 

as 

43 
m 

T-l 

O 

43 

0) 
#> 

43 

'So 
O 
Ph 

o 

43 

.6 

43 

'S3 
o 
ft 

-<-<    43 
O    GO 

m 

o 

43 

73 

CS 

o 

43 
(B 
#> 

'53 
o 

Ph 

o 

>    • 
.15  § 

g-S 

43  5 

b0°* 

|8 

43  4> 

o  tn 
Ph 

4> 

in 

43 

T3 
u 

CO 

o 

43 

.8 

'tn 

O 

Ph 

Si 

43    m 

_>   43 

'43  "i3 

43  4> 

u  tn 

S-i  i-l 

m 

4> 

m 

43 

4> 

CO 

0 

4» 

.6 
43 

oj 
bO 

43 

City  dwellers 

Town  dwellers. . . . 
Country  dwellers . 

40 
53 
66 

28 
40 
54 

70. 
75. 

81.8 

7 

9 

10 

87.5 
92.5 
96.9 

1 

2 
0 

90. 

96.2 
96.9 

4 
2 
2 

Totals 

159 

122 

76.7 

26 

93. 

3 

94.9 

8 

A  similar  test  was  made  at  the  U.  S.  Army  General  Hos- 
pital No.  21,  Denver,  Colorado.1  One  hundred  soldiers  be- 
tween 21  and  30  years  of  age  of  the  Medical  Department 
detachment  of  the  hospital  were  tested  with  the  cutaneous 
inoculation  of  tuberculin.  In  the  first  test  71  were  posi- 
tive, 29  negative.  The  negative  cases  received  a  second 
inoculation  after  five  days,  24  becoming  positive  and  5  re- 
maining negative,  giving  a  positive  percentage  for  the  two 
inoculations  of  95  per  cent.  One  of  the  five  negative  cases 
was  discharged  at  this  time,  the  remaining  four  were  tested 
by  subcutaneous  injections  of  tuberculin.  All  were  nega- 
tive to  1  mg.  old  tuberculin.  All  likewise  failed  to  react 
to  5  mg.  To  the  injection  of  10  mg.  three  reacted  posi- 
tively and  one  negatively.  A  fourth  injection  of  20  mg. 
was  given  to  the  one  who  remained  negative.  There  was 
no  rise  of  temperature  after  this  injection  but  the  reaction 


1  Lieut.  R.  K.  Stacey,  Med.  Corps,  U.  iS.  A. 
Surgeon  General,  U.  S.  A. 


Unpublished  Report  to  the 


98  EPIDEMIOLOGY  OP  TUBERCULOSIS 

was  considered  positive  on  account  of  the  depot  reaction  — 
redness  and  swelling  at  the  point  where  the  tuberculin  had 
been  injected.  A  comparison  of  radiographs  of  this  man 
taken  after  the  first  and  fourth  injections  showed  an  ob- 
scuration in  the  second  radiograph  of  certain  markings 
which  had  been  clear  in  the  first,  from  which  it  was  in- 
ferred that  a  focal  reaction  had  occurred.  The  four  cases 
which  were  given  the  subcutaneous  test  were  all  country 
boys  from  Nebraska,  Kansas,  Oklahoma  and  New  Mexico, 
respectively,  with  no  family  history  of  tuberculosis. 
Although  the  radiographs  of  all  four  showed  what  were 
regarded  as  evidences  of  old  tuberculous  lesions  of  the  deep 
lung  they  would  probably  have  been  considered  as  unin- 
fected with  tuberculosis  if  the  subcutaneous  test  had  not 
been  resorted  to.  Disregarding  the  single  individual  who 
fell  out,  we  have  a  probable  100  per  cent,  of  active  reac- 
tions in  99  individuals.  The  tuberculin  was  used  full 
strength  in  both  of  the  above  series.  The  high  degree  of 
reaction  to  tuberculin  in  our  soldiers  shown  by  the  fore- 
going tests  is  noteworthy  on  account  of  the  idea,  based  on 
insufficient  evidence,  which  has  been  entertained  by  some 
that  the  men  of  our  army  are  largely  unimmunized  by  pre- 
vious tuberculization  and  are  therefore  in  danger  of  acquir- 
ing a  primary  tuberculosis.  The  results  above  quoted  cor- 
respond closely  with  those  of  Freund,1  who  submitted  61 
Austrian  soldiers  to  the  cutaneous  test  with  undiluted 
tuberculin  and  obtained  58  positive  reactions,  or  95.1  per 
cent.2 
We  may  conclude  from  the  foregoing  that  healthy  adults 

'Wien.  Med.  Wochenschr.     1908,  Nos.  22  and  23. 

2  F.  Hamburger  reports  that  Gyenes  and  Weissmann  examined  470  sol- 
diers, patients  who  were  not  suspected  of  active  tuberculosis,  by  means 
of  the  "  stich  "  reaction  and  obtained  positive  results  in  98  per  cent,  of 
the  cases.    Wien.  Med.  Wochenschr.     1917,  p.  529. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS  99 

in  our  civilization  react  about  as  freely  as  the  clinically 
tuberculous  to  the  cutaneous  test  with  undiluted  tuberculin. 
In  both  classes  the  reactions  are  negative  in  about  five  per 
cent,  of  cases.  If  advanced  cases  are  excluded,  the  indi- 
viduals who  are  insensitive  to  the  von  Pirquet  test  will  be 
found  as  a  rule  to  react  to  larger  dosage  with  tuberculin. 
Whether  racial  peculiarities  influence  tuberculin  reactivity 
is  a  question  that  invites  farther  investigation.  Tuberculin 
should  always  be  used  undiluted  when  the  cutaneous  test  is 
employed  in  epidemiological  investigations. 

For  the  cutaneous  test  the  skin  should  be  cleansed  with 
alcohol,  not  with  iodine.  Von  Pirquet  advises  the  use  of  a 
'  borer,"  a  dull  instrument  for  abraiding  the  skin.  If  this 
is  used,  there  is  always  some  inflammatory  reaction  in  the 
controls  and  the  question  as  to  a  positive  result  is  decided 
by  comparative  measurements  of  the  papule  of  the  control 
and  of  the  tuberculinized  abrasion.  Von  Pirquet  demands 
that  the  papule  should  measure  5  mm.  more  than  the  con- 
trol in  order  to  be  considered  positive.  An  insufficient 
"  bore  "  is  shown  by  the  absence  of  scab.  A  better  form 
of  abrasion  is  produced  by  scratching  the  skin,  without 
drawing  blood,  but  deeply  enough  so  that  minute  red  points 
appear  in  the  course  of  the  scratch.  A  scratch  untreated 
is  made  as  control.  Koch's  old  tuberculin  is  generally  used. 
Much  distinguishes  three  degrees  of  the  positive  reaction, 
slight,  normal  and  severe.  The  positive  result  is  shown  by 
an  inflammatory  infiltration  expressed  by  redness  and 
swelling.  This  appears  in  from  four  to  six  hours  and 
reaches  its  maximum  in  from  24  to  48  hours.  The  lesion 
is  more  distinct  upon  thin  than  upon  thick  skin.  The  inner 
surface  of  the  forearm  is  the  best  place  for  the  scarifica- 
tion. Special  types  of  the  reaction  have  been  described: 
the  premature,  the  persisting  and  the  late.    The  premature 


100  EPIDEMIOLOGY  OF  TUBERCULOSIS 

reaction  has  a  rapid  course  and  slight  intensity,  reaching 
its  maximum  in  ten  or  twelve  hours  and  disappearing  on 
the  second  day  at  the  latest.  It  is  supposed  to  occur  in 
cases  of  manifest  tuberculosis  which  are  not  improving. 
The  other  two  types  are  found  in  cases  with  inactive 
lesions.  The  persisting  reaction  begins  like  the  normal 
reaction  but  continues  for  a  much  longer  time,  while  the 
late  reaction  is  slow  in  making  its  appearance  as  well  as  in 
receding.  The  cases  should  be  examined  in  24  and  48 
hours. 

A  more  sensitive  test  than  the  cutaneous  inoculation  is 
found  in  what  is  known  as  the  combined  depot  and 
"  stich  "  (puncture)  reaction.  If  the  first  cutaneous  inoc- 
ulation is  negative,  a  second  is  given  after  three  days.  If 
the  second  inoculation  is  also  negative,  give  a  subcutaneous 
injection  of  1  mg.  If  this  injection  is  negative,  according 
to  Hamburger,1  active  tuberculosis  may  be  excluded,  the 
only  exception  being  cases  with  very  advanced  or  miliary 
tuberculosis  in  the  last  days  before  death,  which  would  not, 
of  course,  be  subjected  to  the  test.  A  tuberculin  reaction 
is  not  at  all  dangerous  to  inactive  tuberculosis;  one  need 
have  no  fear  of  rendering  such  foci  active  by  exciting  the 
reaction.  On  the  contrary,  it  is  probable  that  such  a  reac- 
tion is  of  benefit  in  arousing  the  immunizing  powers  of  the 
organism,  and  in  such  cases  tuberculin  injections  even 
appear  to  stimulate  the  metabolism,  sometimes  producing 
increase  of  weight.  The  cases  of  inactive  tuberculosis,  in 
short,  are  the  very  cases  that  are  most  benefited  by  the  use 
of  tuberculin,  although,  of  course,  they  need  its  help  less 
than  those  with  active  disease.  It  is  perfectly  safe,  there- 
fore, to  continue  the  test  with  larger  doses.     After  waiting 

'Die  Tuberkulose  des  Kindesalters,  1912.     The  directions  for  preparing 
tuberculin  are  taken  in  great  part  from  this  work. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS        101 

three  days,  repeat  the  dose  of  1  mg.;  if  the  result  is  still 
negative,  follow  successively  at  three-day  intervals  with 
doses  of  5  rag.  and  10  rag.  If  10  mg.  is  negative,  repeat  the 
same  dose,  after  which,  if  the  result  continues  to  be  nega- 
tive, the  dose  may  be  increased  to  20  mg.  The  size  of  the 
injection  should  not  exceed  1/10  c.c,  nor  should  a  stronger 
dilution  than  1/10  be  employed.  If  necessary  in  large  dos- 
age, more  than  one  injection  may  be  given.  The  syringe 
used  should  be  graduated  in  tenths  of  a  c.c.  The  necessary 
dilutions  are  prepared  either  with  a  pipette  graduated  in 
1/10  c.c.  or  with  a  not  graduated  pipette,  counting  the 
drops.  For  diluting  fluid  use  0.8  per  cent,  sodium  chloride 
solution,  containing  0.5  per  cent,  carbolic  acid.  Put  9/10 
c.c,  or  9  drops,  diluting  solution  into  a  watch-glass  with  a 
pipette.  With  a  second  pipette  take  tuberculin  from  the 
original  bottle  and  add  1/10  c.c,  or  one  drop,  to  the  watch- 
glass.  Mix  well,  and  from  this  ten-fold  dilution  put  1/10 
c.c.  or  one  drop,  into  a  second  watch-glass  with  9/10  c.c. 
or  nine  drops  of  diluting  solution.  Mix  again,  and  from 
this  1/100  dilution  put  1/10  c.c.  or  one  drop  into  a  third 
watch-glass  with  9/10  c.c.  or  9  drops  of  diluting  solution. 
This  gives  solution  1/1000,  etc. 

To  inject  1  mg.  give  1/10  c.c.  of  the  1/100  dilution.  For 
5  mg.  add  an  equal  amount  of  diluting  solution  to  a  few  c.c. 
or  drops  of  the  1/10  dilution,  making  dilution  1/20.  Of 
this  dilution  1/10  c.c.  equals  1/200  gm.  or  5  mg.  Of  course, 
10  mg.  is  contained  in  1/10  c.c.  of  the  1/10  dilution. 

The  needle  of  the  hypodermic  syringe  should  be  pushed 
well  in,  but  its  tip  should  lie  directly  beneath  the  skin.  A 
positive  reaction  is  shown  locally  by  a  reddened  and  tender 
swelling  where  the  point  of  the  needle  has  been  (depot 
reaction),  also  by  redness  of  the  point  of  puncture  of  the 
skin,  and,  not  as  frequently,  of  the  canal  of  the  puncture 


102  EPIDEMIOLOGY  OP  TUBERCULOSIS 

(stich-reaction).  The  redness  and  infiltration  begin  in 
4  to  8  hours,  generally  reach  a  maximum  in  24  hours  and 
should  last  at  least  three  days.  The  breadth  of  the  swelling 
is  about  10  mm.  In  the  less  sensitive  cases  the  "  stich  " 
reaction  may  be  absent,  though  the  depot  reaction  is 
present.  If  the  depot  reaction  is  distinct,  the  result  may 
be  considered  positive  though  there  be  no  rise  of  tempera- 
ture, provided  that  the  size  and  strength  of  the  doses 
already  specified  be  not  exceeded.  There  may  however  be 
some  redness  and  swelling  due  to  the  irritant  effect  of  the 
tuberculin  when  the  1/10  dilution  is  used  for  doses  of  10 
mg.  or  more.  In  case  of  doubt  a  control  injection  can  be 
made  by  evaporating  a  four  per  cent,  glycerine  bouillon  to 
one-tenth  of  its  volume  in  a  water-bath  and  using  this 
diluted  to  the  same  strength  and  in  the  same  dose  as  that 
of  the  tuberculin  injection  with  which  it  is  to  be  compared. 
The  temperature  should  be  taken  after  the  injection  at  not 
more  than  three  hours'  intervals,  at  least  during  waking 
hours.  Hamman  and  Wolman1  regard  an  elevation  of  one 
degree  Fahrenheit  above  the  previous  maximum  tempera- 
ture as  sufficient  to  indicate  a  positive  reaction,  but  no 
subcutaneous  injection  of  tuberculin  should  be  given  until 
it  has  positively  been  ascertained  that  the  temperature  of 
the  subject  is  perfectly  normal.  Care  should  be  taken  to 
follow  up  the  cases  injected  subcutaneously,  for  if  a  febrile 
reaction  to  tuberculin  is  overlooked  and  increasing  doses 
continue  to  be  given  at  short  intervals  the  result  may  be  a 
temporary  insensitiveness  to  tuberculin,  even  in  the  largest 
doses,  a  condition  which  would  lead  to  misinterpretation 
of  the  nature  of  the  case. 

The  above  method  is  a  safe  one  for  the  determination  of 

'Tuberculin  in   Diagnosis  and  Treatment,  1912. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS         103 

tuberculin  sensitiveness  of  healthy  persons  belonging  to  the 
fairly  well  immunized  community.  The  sick  who  are  sus- 
pected to  have  tuberculosis  and  known  tuberculous  cases 
should  not  be  given  tuberculin  subcutaneously  for  diagnos- 
tic purposes.  But  if  the  cutaneous  test  shows  a  small  per- 
centage of  positive  cases  so  that  immunization  may  be  in- 
ferred to  be  absent  or  very  imperfect,  it  would  be  more 
prudent  not  to  employ  tuberculin  subcutaneously  in  the 
doses  recommended  above,  the  danger  being  the  presence  of 
a  masked  primary  tuberculosis  though  the  skin  fail  to  react. 
Dependence  would  be  placed  solely  upon  the  cutaneous  test 
for  the  epidemiological  investigation  of  such  a  group.  If 
the  determination  of  special  cases  should  be  regarded  as 
important,  give  doses  subcutaneously  of  from  0.0001  mg. 
to  0.1  mg.  within  48  hours  after  the  negative  skin  reaction 
and,  in  case  repetition  is  necessary,  following  with  the  suc- 
ceeding doses  at  24  hours'  intervals  in  order  to  avoid  febrile 
reactions,  the  result  being  read  from  the  stich  reaction. 
This  method  has  chiefly  been  employed  in  the  diagnosis  of 
the  tuberculosis  of  young  children,  but  there  seems  to  be  no 
reason  why  it  should  not  be  used  in  the  case  of  unimmu- 
nized  adults.  An  accurate  physical  examination  should  of 
course  be  the  invariable  preliminary  to  the  diagnostic  use 
of  tuberculin  by  subcutaneous  injection. 

A  radiograph  of  the  lungs  and  examination  with  the 
fluoroscope  in  the  oblique  diameters  of  the  thorax  for 
glandular  masses  at  the  hilus  and  elsewhere  in  the  central 
shadow  may  throw  light  upon  some  cases. 

Under  the  inspiration  of  Calmette  the  cutaneous  tuber- 
culin test  has  been  used  in  many  of  the  French  colonies  as 
a  means  of  ascertaining  the  degree  of  tuberculization  of  the 
communities,  the  strength  of  the  tuberculin  used  under  his 
instructions  having  been  25  per  cent.    It  has  also  been 


104  EPIDEMIOLOGY  OF  TUBERCULOSIS 

employed  in  some  of  the  German  possessions  in  Africa  and 
in  the  Pacific.  The  data  obtained  are  fragmentary  and 
inadequate  but  convey  some  interesting  and  valuable  facts 
in  corroboration  of  the  views  that  have  been  expressed. 

At  Reunion,  of  846  children,  one  to  fifteen  years  of  age, 
344  were  positive  for  the  skin  test,  or  40.6  per  cent. ;  of  380 
persons  fifteen  years  or  over  308  were  positive  or  81  per 
cent.1  At  Guadeloupe  children  one  to  fifteen  years  of  age 
were  positive  in  38  per  cent. ;  persons  over  fifteen  years  of 
age  in  41.6  per  cent. ;  at  Martinique  children  one  to  fifteen 
years  in  35.6  per  cent. ;  persons  over  fifteen  in  57  per  cent.2 
The  results  in  these  old  colonies  may  be  compared  with  Cal- 
mette's  findings  at  Lille,  where  of  366  children  five  to  fifteen 
years  of  age  81.4  per  cent,  and  of  236  over  fifteen,  87.7  per 
cent,  reacted.  From  Tonkin  it  is  reported  that  of  884  per- 
sons over  fifteen  years  of  age,  369  were  positive  to  the  skin 
reaction  or  43.7  per  cent.  At  Hue,  in  Anam,  of  699  persons 
thirty-one  to  seventy  years  of  age  who  were  tested,  429 
were  positive  or  63.5  per  cent.3  Students  of  the  colleges  of 
the  Mandarinate,  teachers  and  high  officials,  127  in  num- 
ber, gave  90  positive  reactions  or  70.8  per  cent.  Of  58  pris- 
oners 41  were  positive  or  80.1  per  cent.  Such  reactions  to 
25  per  cent,  tuberculin  show  a  tuberculization,  of  the  higher 
classes  at  least,  in  Anam  which  is  practically  equivalent  to 
that  of  Europe. 

Salecker  reports  of  the  Ladrones  that  investigations  with 
the  von  Pirquet  reaction  show  that  different  groups  of  the 
population  of  these  islands  react  very  differently,4    Among 

1  Enqu&te  sur  l'Epidc5miologie  de  la  Tuberculose  dans  les  Colonies 
Franchises.    A.  Galmette,  Ann.  de  l'lnstitut  Pasteur.     Vol.  26,  1912,  p.  497. 

:Xoc,  Bull,  de  la  Soc.  Path.  Esot.    Vol.  6,  1013,  p.  368. 

•Bernard,  Koun  and  .Meslin,  Bull.  Soc.  Path.  Trop.     1912,  p.  234. 

4  Arch.  f.  S'chiffs-u.  Tropenhyg.  1915,  No.  4,  Abstr.  Deutsche  iMed. 
Wochenschr.     1915,  p.  1080. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS        105 

the  chief  people,  the  Chamorros,  who  have  lived  for  cen- 
turies in  close  contact  with  the  Spaniards  and  are  largely 
half-breeds,  tuberculosis  in  its  extension  and  character  cor- 
responds to  that  of  Europe.  The  Saipans,  who  emigrated 
from  the  Carolinas  80  years  ago,  a  strong  and  vigorous 
tribe,  had  positive  reactions  in  only  about  one-third  of  the 
cases,  but  in  another  group  recently  arrived  from  the  Caro- 
linas 70  per  cent,  were  positive.  Another  group  showed  no 
positive  reactions  at  all  with  the  single  exception  of  a  girl 
who  had  worked  in  the  house  of  a  Chamorro.  The  course 
of  tuberculosis  was  malignant  only  in  the  Carolinians,  who 
also  had  the  proportionally  greater  number  of  cases  of 
manifest  disease.  These  results  show  how  impossible  it  is 
to  determine  the  true  status  of  a  mixed  population  without 
extended  investigations. 

The  town  of  St.  Louis,  in  Senegambia,  became  a  French 
colony  in  the  17th  century.  Its  inhabitants  have  therefore 
long  been  in  contact  with  Europeans.  At  the  same  time 
the  natives  inland  have  probably  been  little  influenced. 
Apparently  the  population  of  the  seacoast  is  reinforced  by 
accessions  from  the  interior  for  the  rate  is  lower  than  would 
be  expected.  At  St.  Louis  the  test  was  made  by  Bourret 
and  Bourrague1  upon  laborers  of  the  military  hospital,  the 
pupils  of  public  schools  and  the  sick  at  the  dispensary, 
groups  especially  likely  to  have  been  exposed  to  tuberculous 
infection.  Of  1573  children,  one  to  fifteen  years  of  age, 
280  were  positive  or  17.8  per  cent.,  and  of  957  persons  over 
fifteen,  146  were  positive,  or  15.2  per  cent.  Here  the 
children  are  infected  in  larger  percentage  than  their  elders 
from  which  it  might  be  concluded  either  that  there  was 
some  source  of  infection  at  the  schools,  or  that  among  the 

•Bull.  Soc.  Path.  Exot.    Vol.  6,  1913,  p.  11. 


106  EPIDEMIOLOGY  OF  TUBERCULOSIS 

adults  examined  there  had  been  a  recent  accession  of  un- 
protected persons.  At  Leopoldville,  in  the  Belgian  Congo, 
the  cutaneous  reaction  of  the  apparently  healthy  was  exam- 
ined, excluding  hospital  patients.  Fourteen  of  359  work- 
men of  the  shops  at  the  port  reacted  positively;  in  twelve 
the  reaction  was  slight  or  doubtful  and  333  were  negative. 
It  is  stated  that  those  who  gave  a  positive  reaction  did  not 
appear  to  be  in  good  health.  Seventy-five  agricultural 
laborers  and  113  inhabitants  of  a  distant  native  village 
gave  one  slight  or  doubtful  reaction  in  each  group. 
Mouchet1  estimates  the  positively  reacting  percentage  of 
the  population  at  7  per  cent,  and  remarks  that  it  reacts  to 
tuberculin  like  the  European  infant.  Correspondingly  the 
nature  of  tuberculous  lesions  found  by  him  at  autopsy 
points  to  primary  tuberculosis.  Wagon3  tested  100  adults 
in  French  Guinea  with  tuberculin  and  obtained  twelve  posi- 
tive reactions.  But  one  of  the  twelve  was  a  prisoner  with 
no  history  and  the  remaining  eleven  were  all  men  not 
native  to  the  country  (depayses)  and  had  occupations  which 
had  long  kept  them  in  contact  with  Europeans  or  Syrian 
merchants.  The  genuine  natives  therefore  all  reacted  nega- 
tively in  this  series. 

On  the  Ivory  coast  SoreP  found  12.4  per  cent,  positive 
reactions  among  405  of  the  natives  of  a  small  town  on  the 
coast,  and  at  Bassam  he  obtained  26  positive  reactions  or 
20.9  per  cent,  in  128  adult  natives  who  worked  at  the 
wharves,  in  the  ship-yards,  etc.  But  at  Bonake,  350  kilo- 
meters from  the  coast,  a  place  not  yet  reached  by  the  rail- 
road, Arlo,  according  to  Sorel,  obtained  only  two  per  cent, 
of  positive  results.     Evidently  here  the  amount  of  tubercu- 


1  Bull.  Soc.  Path.  Exot.     Vol.  6,  1913. 

2Le  Caduefie.    Vol.  10,  1910,  p.  52. 

3  Bull,  de  la  Soc.  Path.  Exot.    Vol.  5,  1912,  p.  855. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS        107 

lous  infection  is  directly  as  the  closeness  of  contact  with 
Europeans  or  other  tuberculized  individuals.  Sorel  how- 
ever infers  that  the  blacks  are  naturally  highly  resistant  to 
tuberculosis  but  that  their  resistance  is  broken  down  by 
addiction  to  alcohol,  which  is  naturally  the  more  abundant 
the  better  the  means  of  communication,  a  view  which  is 
unfortunate  in  that  it  tends  to  befog  the  main  issue  —  the 
protection  of  the  unimmunized  natives  against  massive  in- 
fections with  tuberculous  virus.  In  German  East  Africa, 
in  the  town  of  Kilwa,  5*8  negro  school  children  gave  a  posi- 
tive reaction  in  22.4  per  cent,  and  17.4  per  cent,  of  98 
negroes  (mostly  "  boys  "  in  Hindoo  retail  shops)  and  25.4 
per  cent,  of  79  Hindoos  were  positive.  Peiper1  believes 
that  the  Hindoos  are  the  bearers  of  contagion  to  the  blacks. 
The  coast  cities  where  the  Hindoos  come  first  and  stay  long- 
est are  most  infected.  At  Daressalem,  Manteufel2  found 
25.6  per  cent,  of  native  children  and  30.9  per  cent,  of  Hin- 
doo children  to  give  a  positive  reaction,  while  the  adult 
natives  and  the  adult  Hindoos  had  a  positive  reaction  in 
only  22.4  and  22.3  per  cent,  respectively.  At  Tanga,  Miiller 
tested  600  patients  of  the  native  hospital  without  selection.3 
Of  these,  although  there  were  only  three  clinically  demon- 
strable cases  of  tuberculosis,  200  were  positive  to  the  skin 
test,  showing,  he  says,  a  greater  degree  of  tuberculization 
than  has  hitherto  been  assumed. 

From  Kamerun,  Zieman4  reports  that  of  the  Bantu  sol- 
diers, men  from  various  tribes,  91  men  were  examined  of 
whom  4  or  4.4  per  cent,  were  positive.  Of  82  women  three 
and  of  62  children  two  were  positive.     But  80  negroes,  men, 

1Arch.  f.  Schiffs-u.  Tropenhyg.  Vol.  16,  1912,  p.  431.  Also:  Idem.  Vol. 
15,  1911,  Beiheft  2, 

2  Idem.    Vol.  18,  1914,  p.  711. 

3  Arch.  f.  Schiffs-u.  Tropenhyg.    Vol.  18,  1914,  p.  690. 
♦Centralbl.  f.  Bakt.  Ite.  Abtlg.  Originale.     Vol.  70,  p.  118. 


108  EPIDEMIOLOGY  OF  TUBERCULOSIS 

women  and  children,  from  the  highlands  were  all  negative 
except  one  man,  who  had  lived  on  the  coast  as  a  soldier. 
On  the  other  hand,  in  a  wretched  group  of  exiled  Hotten- 
tots, of  34  adults,  22  gave  a  positive  reaction  and  of  these 
15  had  signs  of  apical  catarrh.  Three  of  the  twelve  adults 
with  negative  reaction  had  the  same  physical  signs. 

In  Kaiser  Wilhelmsland  (New  Guinea  or  Papua)  Ker- 
sten1  tested  22  children  and  39  women  on  the  Waria  River 
and  42  children  and  17  women  on  the  Morobe  River,  all  of 
whom  were  negative,  but  found  that  of  74  men  of  the  Waria 
group  17  were  positive  (23  per  cent.),  and  of  56  men  of 
the  Morobe  group  15  or  26.8  per  cent,  gave  a  positive  reac- 
tion, explaining  the  preponderance  of  infection  among  the 
men  by  the  fact  that  they  had  been  hired  from  time  to  time 
as  laborers  since  1903.  The  Namalas  are  only  in  super- 
ficial contact  with  the  whites,  although  men  of  the  tribe 
have  worked  on  plantations  since  the  early  nineties.  Of 
these  44  adult  males  were  all  negative,  but  of  44  natives  at 
the  station  12  or  27.3  per  cent,  were  positive.  In  the 
Bogadjin  villages  near  Friedrich  Wilhelmshafen  36  children 
6  years  of  age  or  less  were  all  negative  and  of  50  older 
children  not  more  than  14  years  of  age,  four  were  positive 
while  of  76  adult  women  15  or  19.7  per  cent,  were  positive, 
and  in  85  men  there  were  23  positive  reactions  (27.1  per 
cent.).  These  men  had  been  constantly  in  contact  with 
whites,  Malays  and  Chinese  since  the  beginning  of  the  set- 
tlement. In  New  Pomerania  (an  island  near  Papua,  also 
known  as  New  Britain)  in  a  region  remote  and  rarely  vis- 
ited by  Europeans,  Kopp2  found  that  of  170  men,  39  or 
22.9  per  cent.,  and  of  118  women  7  or  5.9  per  cent.,  were 

1  Arch.  f.  Sehiffs  u-  Tropenhyg.     Vol.  19,  1915,  p.  101. 
'Idem.     Vol.  17,  1913,  p.  729. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS       109 

positive,  while  only  two  of  113  children  or  1.8  per  cent, 
reacted  positively. 

On  the  east  coast  of  Sumatra  the  large  "  plantation  com- 
panies "  employ  about  20,000  laborers  in  the  cultivation  ol 
rubber  trees.  Of  these,  about  nineteen-twentieths  are 
Javanese,  the  remaining  being  Chinese  and  coolies  from 
Further  India.  Heinemann1  states  that  in  284  cases  dead 
from  other  causes,  only  four  showed  an  old  apical  tubercu- 
lous focus.  Of  69  deaths  which  he  reports  in  detail,  he  found 
that  59  were  due  to  tuberculosis.  Cheesy  lymph-gland 
tuberculosis  was  the  most  prominent  affection  in  many  of 
the  fatal  cases.  Those  in  which  pulmonary  tuberculosis 
was  present  had  usually  the  cheesy  broncho-pneumonic  or 
lobar  pneumonic  type.  The  proliferative  form  of  pulmo- 
nary tuberculosis  with  manifestations  of  a  reparative  ten- 
dency was  rare.  Bone  tuberculosis  was  found  but  once, 
tuberculides  of  the  skin  and  lymphoma  of  the  neck  never. 
The  course  of  the  tuberculosis  was  generally  rapidly  fatal. 
Evidently  we  have  here  primary  tuberculosis  with  only  a 
small  admixture  of  cases  in  which  there  was  any  evidence 
of  immunity  from  previous  infection  with  tuberculosis. 
Formerly  the  Javanese  laborers  were  very  carefully 
selected  for  the  Sumatra  plantations  in  the  rural  districts 
of  Java.  The  immediate  isolation  of  all  manifest  tuberculo- 
sis and  the  removal  of  newly  immigrating  coolies  with  open 
tuberculosis  sufficed  to  keep  down  the  curve  of  tuberculosis 
morbidity.  But  with  the  extension  of  rubber  culture  over 
the  whole  east  coast  of  Sumatra  the  demand  for  laborers 
became  so  great  that  they  were  recruited  from  all  parts  of 
Java,  especially  the  cities,  and  the  former  strictness  of 
selection  was  relaxed  on  account  of  the  pressing  need  of 
men.    With  the  importation  of  7000  additional  coolies  in 

1  Hamburgische  Med.  Ueberseehefte.    Vol.  1,  1914,  p.  34. 


110  EPIDEMIOLOGY   OP  TUBERCULOSIS 

1911,  1912  and  1913  the  rates  of  admission  to  hospital  for 
tuberculosis  increased  from  0.2  to  almost  0.6  per  cent. 
Using  the  cutaneous  tuberculin  test,  Heinemann  found  125 
men  positive  out  of  3580  or  3.5  per  cent. 

It  is  generally  assumed  that  the  members  of  an  unpro- 
tected race  who  give  a  positive  tuberculin  reaction  are 
about  to  fall  ill  with  primary  tuberculosis.  This  did  not 
seem  to  be  the  case  in  this  instance  for  Heinemann  remarks 
that  so  far  none  of  those  with  a  positive  von  Pirquet  reac- 
tion have  developed  manifest  tuberculosis  and  thinks  it  pos- 
sible that  they  had  received  their  infection  in  some  of  the 
cities  of  Java  from  contact  with  Europeans,  Chinese  or 
Arabs,  so  that  the  conditions  of  infectiousness  had  been  sim- 
ilar to  those  of  Europe  (i.  e.,  there  was  an  opportunity  to 
develop  an  immunity  from  a  small  infection) .  Now  the  most 
interesting  fact  is  this :  Heinemann  states  that  in  the  increase 
of  morbidity  from  tuberculosis  it  was  not  the  newly  arrived 
that  fell  sick  but  that  the  greater  part  of  the  patients  were 
the  older  men  who  had  worked  on  the  estates  for  years. 
Only  twice  could  it  be  discovered  that  the  sick  had  been  in 
the  vicinity  of  cases  of  manifest  tuberculosis,  but  they  are 
known  to  have  been  near  men  with  a  positive  reaction  for 
tuberculin.  Accordingly  Heinemann  thinks  that  the  ap- 
parently healthy  bacillus-carriers,  as  occasionally  "  bacillus- 
excreters,"  were  to  blame  for  most  of  the  infections.  These 
investigations  constitute  a  valuable  contribution  to  the 
endemiology  of  tropical  tuberculosis. 

While  the  tropics  furnishes  the  most  fruitful  field  for 
such  observations  the  same  laws  are  seen  to  be  in  opera- 
tion wherever  an  uninfected  population  is  brought  into  con- 
tact with  the  outside  world.  Parrot1  found  at  Duzerville, 
in  Algeria,  that  the  rural  natives  gave  21.2  per  cent,  of  posi- 

'Bull,  de  la  Soc.  Path.  Exot.    Vol.  5,  1912,  p.  802. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS        111 

fcive  reactions  to  the  cutaneous  test,  the  native  villagers  42.8 
per  cent.,  and  remarks  that  it  is  the  natives  who  live  most 
in  contact  with  Europeans  who  are  the  most  infected.  This 
fact  is  shown  on  a  more  extensive  scale  by  the  observations 
of  Metchnikoff  and  his  colleagues  among  the  Kalmucks.1 

t 

From  the  medical  statistics  of  the  Astrakhan  government 
it  appears  that  pulmonary  tuberculosis  is  found  throughout 
the  steppes  but  is  less  frequent  in  the  central  portions  re- 
mote from  the  Russians.  Metchnikoff  found  the  same  to 
be  true  of  tuberculosis  of  the  bones  and  joints.  This  party 
examined  3264  persons,  of  whom  2949  were  Kalmucks,  by 
the  cutaneous  test  with  50  per  cent,  tuberculin.  In  the 
periphery  of  the  region  89.5  per  cent,  of  the  men  and  75 
per  cent,  of  the  women  gave  a  positive  reaction.  In  th» 
central  portions  only  43  per  cent,  of  the  women  were  posi- 
tive. The  men  who  had  64  per  cent,  of  positive  reactions 
were  more  highly  infected  than  the  women  because  they 
came  more  frequently  into  contact  with  the  outside  world. 
The  population  of  the  outer  regions  called  "  sedentary  "  in 
contrast  with  the  nomadic  Kalmucks  give  figures  compar- 
able with  those  of  Europe.  Of  38  Russians  and  adult  Mus- 
sulmen  examined  at  the  Bazar  des  Kalmouks  only  one 
young  girl  of  sixteen  was  negative.  According  to  Metch- 
nikoff, Khlopine,  writing  in  1911,  stated  that  the  adoles- 
cent Kalmucks  pursuing  the  course  of  the  secondary  schools 
in  Astrakhan  do  not  finish  their  instruction.  When  they 
reach  the  fifth  or  sixth  year  they  begin  to  grow  feeble,  be- 
come anaemic  and  finally  develop  tuberculosis.  This  was 
so  generally  true  that  the  school  for  Kalmuck  girls  was 
given  up  and  there  was  even  question  of  transporting  the 
secondary  school  for  boys  from  Astrakhan  to  the  steppes. 

1  Metchnikoff,  Burnet  and  Tarassewitch,  Ann.  de  l'Institut  Pasteur.    Vol. 
25,  1911,  p.  785. 


112  EPIDEMIOLOGY  OF  TUBERCULOSIS 

At  the  Kalmuck  boarding  school  in  Astrakhan  715  pupils 
attended  the  course,  in  the  45  years  from  1865  to  1910.  Of 
this  number  75  died  before  finishing  their  studies,  27  were 
obliged  to  leave  Astrakhan  on  account  of  tuberculosis,  and 
the  remaining  613  shortened  their  course  in  order  to  return 
home.  During  the  later  years  the  mortality  has  dimin- 
ished, no  doubt  because  of  progress  in  tuberculization. 
Thus,  according  to  Khlopine,  the  mortality  which  was  for- 
merly 118  per  1000,  fell  in  the  decade  1895-1905  to  31.7  per 
1000.  It  is  noted  that  certain  students,  physicians,  jurists 
and  orientalists,  have  even  finished  their  course  of  instruc- 
tion, something  never  seen  formerly. 

When  the  scholars  returned  to  Astrakhan  from  the 
steppes  in  October,  they  were  all  tested  by  Metchnikoff  by 
the  von  Pirquet  method.  Of  a  total  of  53  pupils  16  had 
arrived  to  commence  their  studies,  aged  eleven  to  fifteen 
years  and  in  good  health.  Of  these  eight  gave  a  feebly 
positive  reaction.  Of  three  pupils  who  had  lived  more  than 
one  year  at  Astrakhan  only  one  was  negative. 

In  semi-civilized  countries  long  in  touch  with  civilization 
the  percentage  of  positive  skin  reactions  approaches  that  of 
European  communities,  but  is  not  apparently,  as  a  rule,  so 
high.  It  seems  to  be  higher  in  the  better-educated  classes 
than  in  the  poorer  and  more  ignorant  inhabitants,  from 
which  fact  —  the  opposite  to  that  which  obtains  in  Europe 
—  it  may  be  inferred  that  the  conditions  of  semi-civilized 
existence  do  not  make  for  as  thorough  a  tuberculization  of 
the  proletariat  as  is  found  in  the  large  cities  of  a  higher 
civilization.  Correspondingly  it  would  appear  that  the 
type  of  tuberculosis  present  is  often  rather  more  acute  than 
that  with  which  we  are  familiar. 

In  the  countries  more  recently  infected  with  tuberculosis, 
the  percentage  of  positive  skin  tests  is  directly  as  the  close- 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS         113 

ness  of  contact  with  Europeans,  Hindoos,  Chinese  or  other 
tuberculized  individuals.  There  is  an  exact  parallelism 
between  the  cutaneous  reaction  and  the  clinical  course  of 
tuberculosis,  so  that  one  can  be  predicted  if  the  other  is 
known.  Where  chronic  pulmonary  tuberculosis  is  the  pre- 
vailing type,  the  percentage  of  positive  skin  tests  will  be 
high,  where  the  positive  percentage  is  low,  tuberculosis  will 
be  rarer  but  severe  and  acute. 

It  is  especially  important  to  note  that  even  Africans  and 
the  inhabitants  of  the  islands  of  the  Pacific  are  capable  of 
developing  an  immunity,  that  is,  they  become  tuberculin- 
sensitive  but  do  not  immediately  develop  tuberculous  dis- 
ease. How  efficient  an  immunity  that  begins  its  develop- 
ment in  adult  life  will  be  in  preventing  manifest  tuberculo- 
sis or  in  modifying  the  type  of  the  disease  remains  for  fur- 
ther study  to  ascertain.  A  thorough  and  detailed  study  of 
the  incidence  of  tuberculous  infection  upon  the  natives  of 
the  tropics  by  means  of  the  cutaneous  reaction  to  tuberculin 
will  throw  much  needed  light  upon  this  subject. 

If,  as  would  appear  from  the  facts  cited  in  previous  chap- 
ters, the  members  of  a  civilized  community  are  protected  to 
a  large  extent  against  acutely  fatal  tuberculosis  although 
the  disease  is  always  so  widely  prevalent  that  opportunities 
for  infection  must  be  frequent,  it  would  logically  follow 
from  analogy  with  other  infectious  diseases  that  their  im- 
munity depends  upon  their  having  had  tuberculosis.  This 
view  demands  the  assumption  of  so  widespread  a  tubercu- 
lization of  our  race  that  it  has  naturally  encountered  much 
opposition.  Tuberculin  tests  have  rendered  inestimable 
service  by  proving  that  such  tuberculization  does  indeed 
exist.  The  fact  that  nearly  one  hundred  per  cent,  of  civil- 
ized adults  give,  sooner  or  later,  a  positive  reaction  to  tuber- 
culin agrees  with  and  supports  the  findings  of  pathologists 


114  EPIDEMIOLOGY   OF  TUBERCULOSIS 

such  as  Naegeli  and  Burckhardt.  Albrecht  and  Arnstein,1 
examining  for  tuberculosis  the  tracheobronchial  glands  of 
children  six  to  sixteen  years  of  age  with  the  aid  of  the 
microscope  and  of  the  inoculation  of  animals,  found  that  the 
percentage  of  positive  results  agreed  pretty  closely  with  the 
percentage  of  positive  results  obtained  with  tuberculin  by 
Hamburger  in  living  children.  Hamburger  found  in  chil- 
dren seven  to  ten  years  of  age  71  per  cent.,  in  those  of  ten  to 
fourteen  years  94  per  cent,  of  positive  depot  and  stich 
reactions.  Albrecht's  figures  are :  children  six  to  ten  years 
83.6  per  cent.,  ten  to  sixteen  93.3  per  cent,  positive  for 
tuberculosis.  Now  every  one  admits  that  the  reaction  to 
tuberculin  is  a  specific  reaction.  But  the  fact  already  noted 
is  not  sufficiently  appreciated  that  tuberculin,  at  least  as 
now  employed,  does  not  necessarily  reveal  all  of  the  tuber- 
culosis, that  the  von  Pirquet  test  is  a  relatively  coarse  test, 
and  that  the  subcutaneous  reaction  while  permitting  larger 
dosage,  sometimes  fails  in  doses  as  large  as  many  have  the 
courage  to  employ,  though  tuberculosis  may  nevertheless  be 
present.  Similarly,  tubercle  bacilli  may  be  proved  to  be 
present  by  animal  inoculation  and  even  by  growth  on  cul- 
ture media,  though  the  microscope  fails  to  disclose  them, 
and,  on  the  other  hand,  tubercle  bacilli  may  be  found  in 
smears  and  in  tissues  by  the  microscope  and  yet  inocula- 
tion into  animals  of  the  tissues  in  question  may  have  a 
negative  result.  It  is  also  evident  that  no  pathologist  can 
ever  search  long  enough  to  be  absolutely  sure  that  there  is 
no  small  tuberculous  focus  in  the  body  which  he  is  examin- 
ing. We  conclude  therefore  that  failure  to  detect  tubercu- 
losis in  civilized  adults  by  the  various  methods  of  investi- 
gation is  not  necessarily  proof  that  the  individuals  in  ques- 

*  Albrecht    and    Arnstein,    Verhandlungen    d.    Deutsoh.    Path.    Gesellsch. 
1912,  p.  124. 


DIAGNOSIS,  ESPECIALLY  TUBERCULIN  DIAGNOSIS         115 

tion  are  uninfected.  In  other  words,  when  the  negative 
percentages  are  small,  showing  an  extensive  tuberculization 
of  the  community,  the  presumption  is  that  where  nearly  ail 
are  found  infected  all  have  been  exposed,  the  failure  to  find 
evidences  of  tuberculosis  in  this  small  minority  being  due 
to  the  inadequacy  of  the  methods  of  investigation  rather 
than  to  complete  absence  of  infection. 


CHAPTER  VIII 
PROPHYLAXIS  OF  THE  NON-IMMUNIZED 

In  making  a  survey  of  the  situation  of  the  tropical  com- 
munity as  respects  the  tuberculosis  problem,  the  health 
officer  has  first  to  satisfy  himself  as  to  the  degree  of  tuber- 
culization which  exists  in  general  in  the  population.  To 
this  end  he  would  naturally  seek  answers  to  the  following 
questions :  What  is  the  prevalent  type  of  tuberculosis?  Is 
it  pulmonary  tuberculosis  ?  Are  cases  of  pulmonary  tuber- 
culosis usually  of  a  rapid  or  of  a  slow  course?  In  other 
words,  are  there  many  individuals  that  have  had  the  dis- 
ease for  years  with  progressive  emaciation  and  consider- 
able cough  and  expectoration  or  do  the  cases,  as  a  rule,  end 
in  a  few  months?  Do  patients  ever  live  long  or  recover 
after  attacks  of  pulmonary  hemorrhage?  What  is  known 
as  to  bone  and  joint  tuberculosis?  Are  there  humpbacks, 
cases  of  hip- joint  disease?  Have  many  of  the  children  play- 
ing in  the  streets  swollen  glands  of  the  neck?  When  tuber- 
culosis enters  a  family  as  a  manifest  disease,  is  the  entire 
family  swept  away  or,  on  the  other  hand,  is  the  course  slow 
in  members  secondarily  affected  or  again  do  some  escape 
entirely? 

When  tuberculosis  seems  to  end  rapidly  in  death  (allow- 
ance should  be  made  here  for  the  probability  that  many 
cases  will  not  be  recognized  until  the  last  stage  of  the  dis- 
ease) do  the  patients  often  or  ever  have  massive  swelling 
of  cervical,  femoral  and  axillary  glands?  After  what  has 
already  been  said,  the  significance  of  the  above  questions 
will  be  sufficiently  apparent. 

Though  the  von  Pirquet  reaction  as  an  aid  in  the  diagno- 

116 


PROPHYLAXIS   OF  THE   NON-IMMUNIZED  117 

sis  of  the  individual  case  leaves  much  to  be  desired,  it  is 
nevertheless  an  invaluable  method  for  obtaining  expedi- 
tiously, cheaply  and  safely  the  facts  in  a  general  way  as  to 
the  dissemination  of  tuberculosis  in  a  community  or  group 
of  individuals. 

The  degree  of  tuberculization  is,  of  course,  shown 
roughly  by  the  percentage  of  individuals  positive  for  the 
skin  test.  What  is  to  be  thought  of  the  negatively  react- 
ing depends  upon  this  percentage  and  also  the  history  of 
the  case.  Thus  a  native  of  Manila,  who  pretty  certainly 
has  come  into  contact  with  tuberculosis,  if  he  reacts  nega- 
tively, probably  does  so  because  the  dose  of  tuberculin  has 
not  been  large  enough  to  awake  his  reaction,  whereas  in  the 
case  of  a  man  recently  arrived  from  a  remote  rural  district, 
a  negative  reaction  may  well  mean  the  absence  of  an  im- 
munization. It  is  not  likely  that  any  community  will  be 
found  to-day  to  consist  entirely  of  unirnmunized  individuals 
nor,  on  the  other  hand,  are  there  probably  many  communi- 
ties in  the  tropics  which  have  reached  as  high  a  degree  of 
tuberculization  as  that  of  the  large  industrial  communities 
of  northern  countries.  One  class  in  all  communities,  the 
children,  are  exposed  to  the  dangers  of  primary  tuberculo- 
sis. But  little  has  been  done  (much  less  than  might  have 
been  accomplished  if  there  had  been  an  intelligent  appre- 
ciation of  the  epidemiology  of  tuberculosis)  for  their  pro- 
tection in  the  most  highly  civilized  portions  of  the  globe. 
The  desiderata,  of  course,  are  cleanliness,  good  hygiene  in 
general  and,  above  all,  if  in  any  way  possible,  the  separa- 
tion of  the  child  from  known  sources  of  infection ;  in  other 
words,  remove  the  baby  from  the  consumptive  or  the  con- 
sumptive from  his  or  her  family.  One  can  at  least  teach  a 
few  elementary  truths,  for  example,  do  not  chew  the  food 
for  your  children,  do  not  cover  the  heads  of  the  family  at 


118  EPIDEMIOLOGY   OF  TUBERCULOSIS 

night  with  a  blanket  or  mat,  do  not  let  people  live  with  you 
who  have  coughs.     Do  not  let  anyone  spit  on  the  floor. 

In  the  non-immunized  community  the  influence  of  the 
bacillus-carrier  has  already  been  dwelt  upon.  Peddlers 
seem  to  carry  infection  with  their  wares.  According  to 
Calmette1  in  southwestern  Africa  the  Haoussas  (Mussel- 
man  peddlers)  had  a  higher  percentage  of  positive  cutane- 
ous reactions  than  the  natives,  which  was  also  true  of  the 
Syrians.  Both  of  these  classes  are  believed  to  spread 
tuberculous  infection.  Among  the  uncivilized  such  itiner- 
ant vendors  are  a  much  greater  menace  than  they  would  be 
with  us  even  though  we  were  equally  defenseless  against 
tuberculosis,  for  they  not  only  may  carry  infected  wares 
but  they  also  eat  with  the  family  and  sleep  with  the  family, 
and  no  doubt  expectorate  upon  the  floor  with  the  same  free- 
dom as  the  family.  In  the  unprotected  community  regula- 
tions might  well  be  adopted  to  require  this  class  of  persons 
to  lodge  and  to  eat  by  themselves. 

A  great  responsibility  rests  upon  the  physician  in  the 
case  that  groups  of  uninfected  individuals  are  introduced 
into  infected  surroundings  as  when  gangs  of  laborers  are 
brought  from  remote  rural  districts  to  work  in  towns  or  in 
garrisons.  Such  men  should  be  at  once  examined  by  the 
cutaneous  test,  cases  of  manifest  tuberculosis,  if  such  are 
found,  being  of  course  at  once  isolated  and  the  negatively 
reacting  should  be  quartered  separately.  The  positively 
reacting,  in  the  absence  of  signs  of  manifest  tuberculosis, 
could  be  safely  quartered  with  laborers  of  more  thoroughly 
tuberculized  races,  as  the  Chinese  and  Japanese.  These 
considerations  do  not,  however,  apply  with  as  much  force 
if  the  group  in  question  reacts  in  a  large  percentage  to 


tuberculosis.     Vol.  13.   1914.  p.  355. 


PROPHYLAXIS   OF  THE  NON-IMMUNIZED  119 

tuberculin,  which  would,  of  course,  show  that  it  is  pretty 
well  infected. 

The  quartering  of  natives  in  large  barracks,  if  these  are 
hygienically  good,  seems  at  first  sight  a  step  in  advance  in 
sanitation,  ventilation  and  "  police  "  being  easily  kept  much 
better  than  in  crowded  native  huts.    Experience  has  shown, 
however,  that  so  far  as  relates  to  the  communication  of 
infection  this  is  not  the  case.     In  the  Panama  Canal  Zone 
the  death  rate  among  negro  laborers  from  pneumonia  in 
1906  was  18.74,  in  1907  10.61,  but  in  1908  it  was  only  2.60 
per  1000.    General  Gorgas1  ascribes  this  marked  improve- 
ment to  the  fact  that  the  practice  of  quartering  the  negroes 
in  large  barracks  was  given  up  at  this  time.    The  men,  for 
the  greater  part,  were  permitted  to  live  in  huts  with  their 
families  and  to  prepare  their  own  food.     No  doubt  the  re- 
sult was  worse  ventilation  and  worse  food  but  the  dimin- 
ished liability  to  infection  more  than  counterbalanced  these 
disadvantages.    Where  communicable  diseases  prevail,  the 
spread  of  infection  is  best  prevented  by  quartering  the  sus- 
ceptible in  small  units.     In  unprotected  races  these  con- 
siderations apply  as  closely  to  tuberculosis  as  to  pneumonia. 
The  fact  that   they   are   universally   disregarded  with  us 
without  harm  appearing  to  result  therefrom  is  an  excellent 
proof  of  the  extensive  tuberculization  of  our  race.    The  re- 
cent experience  in  our  army  of  the  effect  of  the  introduction 
of  the  cubicle  system  in  preventing  the  spread  of  streptococ- 
cus infection,  pneumonia,  meningitis,  etc.,  is  familiar  to  all. 
If  we  were  as  sensitive  to  the  tubercle  bacillus  as  we  are 
to  the  streptococcus,  acute  tuberculosis  would  long  ago  hav« 
decimated  our  army. 
It  is  to  be  expected  that  the  unprotected  native  will  come 


xJour.  Am.  Med.  Assn.     Vol.  62,  1914,  p.  1855. 


120  EPIDEMIOLOGY   OF  TUBERCULOSIS 

into  contact  with  the  tubercle  bacillus.  It  is  the  duty  of 
the  physician  to  minimize  the  opportunities  for  massive  in- 
fection. Isolation  of  healthy  laborers  in  the  strict  sense  of 
the  word  is,  of  course,  impracticable.  In  fact,  working  in 
the  fields  with  the  already  tuberculized,  where  contact 
would  rarely  be  intimate  and  where  ejected  tubercle  bacilli 
are  likely  soon  to  become  harmless  by  exposure  to  the  sun, 
does  not  necessarily  result  in  infection.  This  is  almost 
inevitable,  however,  if  the  unprotected  eat  and  sleep  with 
bacillus-carriers.  It  is,  of  course,  of  extreme  importance 
that  cases  of  "  open  "  tuberculosis  shall  be  isolated  as  soon 
as  detected.  They  should  not  be  treated  in  hospital  wards 
occupied  by  uninfected  natives  sick  with  other  diseases. 
The  usual  precautions  as  to  disinfection  and  the  destruction 
of  tuberculous  sputum  should  be  carried  out  with  extreme 
care.  They  are  much  more  necessary  than  in  a  race  as 
thoroughly  tuberculized  as  is  our  own. 

On  account  of  the  almost  universal  immunization  of  our 
race  from  early  tuberculous  infection,  our  sense  of  tuber- 
culosis as  a  communicable  disease  has  become  blunted.  But 
tuberculosis,  as  Hamburger  says,  is  really  as  infectious  as 
measles.  And  nowhere  better  than  in  the  tropics  do  we 
see  how  terrible  a  disease  it  is  when  it  comes  as  a  massive 
infection  upon  the  entirely  unprotected  individual.  Bear- 
ing these  facts  in  mind,  we  must  necessarily  change  our 
views  as  to  the  danger  of  introducing  the  consumptive  into 
the  community.  That  which  seems  and  is  a  venial  offense 
if  the  community  is  immunized  on  the  whole  against  tuber- 
culosis becomes  a  grave  danger  if  there  is  present  a  con- 
siderable number  of  unimmunized  or  very  imperfectly  im- 
munized individuals. 

In  Bengal,  according  to  the   Rev.   Dr.   Kennedy,1  Chota 


»Proc.  Royal  Soc.  of  Med.     Vol.  7,  Pt.  2,  1913-14,  p.  195. 


PROPHYLAXIS   OF  THE  NON-IMMUNIZED  121 

Nagpur  had  so  little  tuberculosis  that  sanatoria  were  built 
there  and  consumptives  came  in  and  lodged  everywhere  in 
the  town,  with  the  result  that  there  was  a  great  increase  of 
tuberculosis  among  the  natives.  South  Africa  has  had  a 
similar  experience  on  a  larger  scale.  Macvicar1  remarks 
that  though  Europeans  suffering  from  phthisis  who  come 
to  South  Africa  for  their  health  have  a  better  chance  of 
recovery  in  the  high  and  dry  districts  than  upon  the  coast, 
the  condition  of  native  life  favor  the  spread  of  tuberculosis 
and  the  fact  seems  to  be  that  it  does  spread  rapidly  where- 
ever  it  has  been  introduced.  At  Burghersdorp,  altitude 
4550  feet,  the  death-rate  for  consumption  among  the  native 
population  is  9.5  per  1000.  At  Beaufort  West,  altitude 
2792  feet,  and  with  a  small  rainfall,  the  native  death-rate 
is  18.5  per  1000.  Both  of  these  towns  have  been  and  still 
are  regarded  as  being  possessed  of  climatic  advantages 
especially  suited  to  the  cure  of  consumption  and  invalids 
from  Europe  go  there  to  live.  The  report  of  the  Medical 
Officer  of  Health  of  Cape  Colony  for  1905  says :  "  It  is  a 
significant  fact  that  centres  such  as  Beaufort  West,  which 
we  formerly  knew  to  be  free  from  the  disease  and  which, 
owing  to  their  peculiarly  favorable  climatic  conditions, 
have  been  chosen  as  health  resorts  by  immigrant  consump- 
tives, should  at  the  present  day  be  the  most  severely  afflicted 
by  the  disease.  Consumption  has  now  secured  so  firm  a 
foothold  among  the  native  and  colored  (i.  e.,  mulatto) 
population  in  Cape  Colony  that  it  is  spreading  in  most  of 
the  towns  and  even  in  towns  in  which  it  is  diminishing 
among  the  Europeans." 

In  Cape  Colony,  a  region  long  civilized,  it  would  not  be 
expected  that  the  native  population  should  have  entirely 
escaped  infection  with  tuberculosis  until  recent  years.     It 

1  South  African  Med.  Rec.    Vol.  4,  p.  133. 


122  EPIDEMIOLOGY  OF  TUBERCULOSIS 

is  an  example,  therefore,  of  a  land  in  which  the  native  popu- 
lation is  imperfectly  immunized  rather  than  entirely  unpro- 
tected against  the  disease.  Accordingly  we  find  that 
hygienic  conditions,  which  would  make  little  difference  if  a 
virgin  population  were  exposed  for  the  first  time  to  a  mas- 
sive tuberculous  infection,  have  a  very  noticeable  effect 
upon  the  native  death-rate  from  tuberculosis.  The  Health 
Officer  of  Cape  Colony  goes  on  to  say :  "  Port  Elizabeth 
and  East  London  would  seem  equally  situated  as  regards 
climate  except  that  Port  Elizabeth  has  a  rainfall  of  21 
inches  while  East  London  (both  are  seacoast  towns)  has 
35  inches.  Yet  in  Port  Elizabeth  the  tuberculosis  death- 
rate  is  15.1  per  1000,  that  of  East  London  3.4  per  1000. 
King  Williamstown,  with  an  altitude  of  1275  feet,  has  al- 
most the  lowest  native  death-rate,  2.5,  while  Grahamstown, 
not  far  distant,  with  an  altitude  of  1741  feet,  has  a  native 
tuberculosis  death-rate  of  8.3  per  1000.  The  conclusion 
from  these  facts  is  that  while  height  above  the  sea  and  dry- 
ness of  climate  are  beneficial  to  patients  under  favorable 
conditions,  in  the  colored  and  native  population  as  a  whole 
their  influence  does  not  appreciably  retard  the  spread  of 
phthisis."  But  the  editor  of  the  South  African  Medical 
Record  adds :  "  In  these  places  which  show  a  compara- 
tively small  increase  in  the  native  mortality  from  tubercu- 
losis, the  general  sanitation  has  been  much  improved  of  late 
years  but  not  in  those  with  a  heavy  increase." 

In  a  paper  published  in  1907,  Kuhn,1  inquiring  whether 
South  Africa  is  suitable  for  the  treatment  of  lung  diseases, 
referred  to  the  experience  at  Davos,  where  no  extension  of 
tuberculosis  from  the  guests  and  immigrating  consump- 
tives took  place,  and  expressed  the  opinion  that  what  ap- 
plies to  Davos  with   equal   hygienic   care   would  apply  to 


'Berl.  Klin.  Wochenschr.     No.  6,  1907. 


PROPHYLAXIS    OF   THE   NON-IMMUNIZED  123 

South  Africa,  where  the  hot  sun  is  the  greatest  enemy  of 
bacilli  throughout  the  year.  Kuhn  refers  to  Sobotta,  who, 
in  a  paper  published  in  the  same  year,1  gave  expression  to 
a  similar  opinion,  namely,  that  the  healthy  population  of 
South  Africa  is  not  threatened  by  the  settling  of  pulmonary 
invalids.  The  slight  density  of  population,  the  sun  and  the 
dry  air  diminish  the  danger  of  infection  and  the  climatic 
advantages  are  more  useful  to  the  healthy  than  to  the  tuber- 
culous patient.  At  Gorbersdorf  and  Falkenstein,  Sobotta 
says,  it  may  be  shown  that  the  native  population  suffered 
less  from  tuberculosis  after  the  erection  of  sanatoria  than 
before.2 

But  new  tidings  from  Cape  Colony  compelled  Kuhn  to 
change  his  views.  He  reports  in  another  paper  published 
in  19083  a  disquieting  extension  of  tuberculosis  in  the  native 
population.  There  was  no  doubt,  according  to  the  state- 
ment of  a  physician,  that  the  disease  had  been  brought  in 
by  the  numerous  consumptives  who  have  visited  the  Karoo. 
It  has  extended  with  marvelous  rapidity  in  consequence  of 
the  carelessness  of  the  patients,  the  ignorance  of  the  nurses 
and  the  absence  of  precautions.  Kuhn  gives  a  table  show- 
ing the  death-rate  from  tuberculosis  in  the  European  and 
colored  population  of  eleven  towns.  The  rate  of  the  colored 
varies  from  6.36  to  14.37  per  1000,  while  that  of  the  whites 
does  not  exceed  2.50  in  any  town  except  in  four  towns, 
three  of  which  are  stated  to  be  the  chief  resorts  of  con- 
sumptives, who  are  largely  responsible  for  the  increased 
mortality.  The  highest  rate,  6.34,  at  Beaufort  West,  is  less 
than  the  lowest  colored  death-rate ;  the  next  highest  is  3.6 
per  1000. 

1  Berl.  Klin.  Wocfasnsahr.     No.  15. 

2  The   sanatoria    of   Brehmer    and   Dettweiler   were    at   Gorbersdorf   and 
Falkenstein  respectively. 

3  Klin.  Jahrbuch  Vol.  20,  1908-09,  p.  513. 


124  EPIDEMIOLOGY  OF  TUBERCULOSIS 

Such  an  experiment  on  the  grand  scale  in  the  epidemi- 
ology of  tuberculosis  as  the  introduction  of  a  large  number 
of  consumptives  upon  a  hitherto  but  slightly  infected  con- 
tinent is  one  that  can  not  be  studied  with  too  great  care. 

The  bright  sun  and  the  dry  air  help  the  consumptive  to 
regain  his  partially  lost  immunity,  but  the  poison  that  he 
brings  with  him,  once  introduced  among  the  almost  unpro- 
tected native  population,  spreads  from  one  to  another  by 
personal  contact  and  carries  them  off  with  frightful  rapid- 
ity, though  they  enjoy  the  same  climatic  advantages. 

Sanitation  is  an  excellent  thing  —  its  benefits  are  appar- 
ent in  the  situation  that  we  are  discussing  —  but  much 
harm  has  been  done  by  giving  credit  to  sanitation  that  is 
really  due  to  a  previous  immunization.  "  Hygienic  care," 
which,  Kuhn  intimates,  explains  why  tuberculous  infection 
was  not  brought  to  the  inhabitants  of  Davos  by  the  visiting 
consumptives,  cannot  prevent  the  "  droplet "  infection  in 
the  vicinity  of  the  tuberculous  nor  the  possibility  of  the 
transmission  of  his  disease  by  means  of  any  article  that  he 
has  touched.  A  sanatorium,  though  it  were  the  best  con- 
ducted sanatorium  in  the  world,  is  a  place  of  the  greatest 
danger  to  the  unimmunized  individual.  That  the  effect  of 
sanitation  in  preventing  infection  is  overrated  is  shown  by 
the  experience  at  another  health  resort  where  for  many 
years  consumptives  lived  in  closest  contact  with  the  inhabit- 
ants of  the  town  without  any  pretence  of  "  hygienic  care." 

The  great  importance  of  clear  ideas  upon  this  subject  jus- 
tifies reproducing  a  portion  of  Werner's  forcible  exposition 
of  the  tuberculosis  situation  at  Lippspringe1  and  Schlan- 
gen:2 

"  The  population   (permanent)    of  Lippspringe  in  1830 


1  Beitr.  z.  Klinik  der  Tub.     Vol.  19,  p.  352. 
Idem.     Vol.  24,  p.  125. 


PROPHYLAXIS   OF  THE  NON-IMMUNIZED  125 

was  1440,  in  1909,  3472.  The  absolute  tuberculosis  mortal- 
ity has  diminished  from  a  yearly  average  of  14.9  in  the 
decade  1831-1840,  the  decade  of  the  opening  of  the  bath,  to 
12.25  yearly  average  in  the  four  years  1906-1909.  The  per- 
centage of  tuberculosis  to  total  mortality  fell  from  31.2  per 
cent,  to  23  per  cent.  The  relation  of  tuberculosis  mortality 
to  1000  inhabitants  fell  from  a  yearly  average  of  9.8  in  the 
decade  1831-1840  to  3.5  in  the  four  years  1906-1909.  It 
may  be  affirmed  that  for  the  decision  of  the  question  as  to 
danger  of  infection  from  tuberculosis,  especially  pulmonary 
tuberculosis,  at  no  time  and  nowhere  in  the  world  has  a 
natural  experiment  of  such  extent  and  duration  been  made 
as  in  Lippspringe.  For  the  period  of  observation  extends 
from  1833,  the  year  of  the  founding  of  the  bath,  to  1909, 
or  76  years.  In  these  76  years  Lippspringe  has  been  vis- 
ited by  170,000  patients  in  round  numbers.  Of  these  cer- 
tainly 80  per  cent,  or  136,000  were  patients  with  pulmo- 
nary tuberculosis,  of  whom  at  least  one-third  or  45,000  were 
so-called  open  cases  with  tubercle  bacilli  in  the  sputum. 
The  number  1000  (of  patients)  was  reached  in  1867,  2000 
in  1874,  3000  in  1897.  In  1896  the  first  state  or  insurance 
sanatoria  appeared.  From  that  time  the  number  of 
patients  rose  rapidly.  In  1906  there  were  more  than  6000. 
From  1906  to  1909  the  average  number  was  about  8000. 
This  yearly  accumulation  of  pulmonary  tuberculosis  does 
not  occur  during  the  entire  year,  but,  especially  in  earlier 
times,  in  the  season  —  April  to  October  —  and  not  over  a 
wide  territory,  but  in  a  small  place  for  the  most  part  rather 
closely  built  up.  Taking  into  consideration  the  number  of 
open  cases  we  may  affirm  that  nowhere  in  the  world  has 
there  been  such  a  dissemination  of  bacilli  as  in  Lippspringe 
since  the  establishment  of  the  bath.  It  is  to  be  considered 
that  until  the  discovery  of  the  tubercle  bacillus  by  far  the 


126  EPIDEMIOLOGY   OF  TUBERCULOSIS 

greater  number  of  doctors  were  not  convinced  of  the  infec- 
tiousness of  tuberculosis,  and  especially  in  Lippspringe,  as 
the  records  show,  the  old  doctrine  of  crasis  prevailed.  No 
one  then  had  the  slightest  idea  of  any  control  of  expectora- 
tion. On  the  contrary,  the  more  frequently  the  patient  ex- 
pectorated the  better  it  was,  for  by  the  sputum  the  dyscra- 
sia  was  removed  from  the  body.  Even  after  the  discovery 
of  the  tubercle  bacillus  the  view  of  the  infectiousness  of 
pulmonary  tuberculosis  spread  very  slowly  among  the  pub- 
lic, the  population  of  Lippspringe  and  the  doctors  there. 
We  may  then  affirm  that  only  with  the  appearance  of  the 
insurance  patients  in  good  numbers  in  1899  was  any  great 
attention  paid  to  controlling  expectoration. 

"  Another  important  fact  which  concerns  the  population 
of  Lippspringe  is  the  following :  The  peculiar  development 
of  the  bath  did  not  lead  at  first  to  the  building  of  large 
hotels  and  sanatoria  in  which  the  guests  were  more  or  less 
isolated  from  the  population,  but  the  latter,  by  the  renting 
of  rooms,  by  nursing  and  by  taking  boarders,  was  from  the 
beginning  in  very  close  contact  with  the  patients.  The 
keeping  of  boarding  houses  increased  greatly,  especially 
after  the  patients  of  public  sanatoria  came  in  large  num- 
bers, so  that  it  may  be  affirmed  that  since  1899  every  second 
house  shelters  and  cares  for  patients.  From  this  it  follows 
that  half  of  the  population  during  the  summer  are  in  con- 
stant contact  with  patients.  This  is  more  true  of  board- 
ing houses  than  of  public  sanatoria,  for  the  patients  in  the 
former  are  much  more  intimately  brought  in  contact  with 
their  landlords  than  are  patients  of  other  classes.  More- 
over but  few  domestics  were  hired.  In  general  the  family 
itself  attended  to  the  housework,  especially  the  cleaning  of 
rooms. 

"  A  further  important  fact  for  the  interpretation  of  this 


PROPHYLAXIS    OF   THE   NON-IMMUNIZED  127 

natural  experiment  is  that  the  population  of  Lippspringe  is 
very  stable.  Emigration  practically  never  takes  place. 
Therefore  every  case  of  infection  must  have  become  known. 

"  We  have  then  a  crowding  together  of  numerous  cases 
of  pulmonary  tuberculosis  in  a  relatively  small  place  and  in 
a  small  community  with  enormous  production  and  dissemi- 
nation of  tubercle  bacilli  for  76  years,  the  absence  of  all 
protective  measures  until  about  1900,  or  67  years,  on  ac- 
count of  the  close  contact  a  very  considerable  exposure  of 
the  population,  together  with  originally  unfavorable 
hygienic  conditions,  a  great  stability  of  the  population  and 
a  diminution  of  the  relative  tuberculosis  mortality  to  about 
one-third  of  its  highest  rate!  From  this  it  follows  with 
certainty  that  the  view  of  the  contagionists  as  to  the  high 
infectiousness  of  pulmonary  tuberculosis  is  totally  false. 
If  it  were  not,  the  whole  population  of  Lippspringe,  under 
the  conditions  described,  must  have  been  infected  and  must 
have  died  out. 

Schlangen  is  3  kilometers  from  Lippspringe.  There  are 
few  tuberculosis  patients  in  Schlangen,  and  until  recently 
there  has  been  no  means  of  direct  communication  between 
this  village  and  Lippspringe.  Many  girls  go  from  these 
villages  to  take  positions  as  servants  during  the  season  at 
Lippspringe.  Infection  if  acquired  would  be  brought  by 
them  to  Schlangen,  where  for  the  most  part  they  remain 
and  marry.  Cornet  says :  "  Most  endangered  are  the  ser- 
vant girls  who  make  beds  and  sweep  rooms." 

"  The  general  mortality  in  Schlangen  has  fallen  from  28 
per  1000  in  1834-1850  to  22  per  1000  in  1896-1908,  and  the 
tuberculosis  mortality  from  11  per  1000  in  1834-1850  to  6 
per  1000  in  1896-1908.  Especial  importance  is  given  to  the 
fall  in  the  general  mortality,  for  if  tuberculosis  is  increased 
the  general  mortality  will  be  increased,  and  this  will  be  true 


128  EPIDEMIOLOGY   OF  TUBERCULOSIS 

whatever  objections  may  be  raised  as  to  the  correctness  of 
the  diagnosis  as  to  tuberculosis.  On  the  other  hand,  if  the 
general  mortality  falls  there  can  be  no  question  of  a  wide- 
spread tuberculous  infection  of  the  community  from  the 
introduction  from  without  of  cases  of  tuberculosis.  The 
total  mortality  is  high,  which  manifestly  points  to  unfavor- 
able hygienic  conditions,  and  the  mortality  from  tuberculo- 
sis in  Schlangen  was  high  at  the  outset  and  in  spite  of  its 
diminution  is  still  high  (for  the  same  reason) . 

"  A  transmission  of  pulmonary  tuberculosis  at  least  to 
adults  through  transient  association  with  cases  of  that  dis- 
ease does  not  exist  and  never  has  existed." 

It  is  evident  that  hygienic  care  will  not  account  for  the 
difference  in  the  effect  produced  by  introducing  the  con- 
sumptive into  Lippspringe  and  into  Cape  Colony.  The 
tuberculous  invalid  is  apparently  harmless  to  the  adults  in 
places  where  tuberculosis  is  a  common  disease.  He  is  a 
dangerous  source  of  infection  in  a  place  where  tuberculosis 
has  been  recently  imported,  though  that  place  be  a  health 
resort  which  has  approved  itself  for  the  cure  of  consump- 
tion. Is  there  any  possible  explanation  of  these  facts  ex- 
cept the  theory  that  exposure  to  tuberculosis  may  result  in 
a  vaccination  against  the  disease?  And  is  it  not  evident 
that  if  resistance  were  not  raised  by  contact  with  the 
tubercle  bacillus  the  races  now  so  highly  tuberculized  would 
have  become  extinct? 

Calmette  says :  "  The  extreme  diffusion  of  tuberculosis 
throughout  the  world  and  the  facility  with  which  it  is  prop- 
agated not  only  by  the  sick  but  also  by  the  immense  num- 
ber of  apparently  healthy  individuals  who  are  carriers,  lead 
us  to  consider  as  impossible  —  perhaps  not  even  desirable 
■ —  the  total  eradication  of  tuberculous  infection  ".* 

1  Loc.  cit. 


PROPHYLAXIS    OF   THE   NON-IMMUNIZED  129 

Viewed  in  this  light  the  practical  prophylaxis  of  tubercu- 
losis ceases  to  be  prophylaxis  of  tuberculous  infection  and 
becomes  prophylaxis  of  tuberculous  disease.  The  task  of 
the  sanitation  becomes  a  plain  though  not  an  easy  one.  It 
is  first  to  diminish  in  every  way  the  opportunities  for  mas- 
sive infection  so  that  as  far  as  may  be  the  initial  dose  of 
tubercle  bacilli  shall  be  small ;  secondly,  to  improve  in  every 
way  possible  the  health  of  the  community,  to  the  end  that 
the  immunity  gained  by  a  fortunate  initial  infection  shall 
not  be  impaired,  that  vaccination  shall  not  be  converted 
into  manifest  and  dangerous  tuberculous  disease. 


CHAPTER  IX 
TREATMENT  OF  TUBERCULOSIS  IN  THE  TROPICS 

Climate  per  se  has  little  responsibility  for  the  incidence 
of  manifest  tuberculosis  except  as  it  may  favor  complicat- 
ing diseases  which  have  an  unfavorable  effect  upon  the  gen- 
eral health.  As  Hirsch  says,  the  mean  level  of  the  tem- 
perature has  no  significance  for  the  frequency  or  rarity  of 
phthisis.  The  bad  reputation  of  the  tropics  as  respects 
tuberculosis  is  largely  due,  first,  to  the  fact  that  climatic 
conditions  are  blamed  for  the  rapid  extension  and  fatal 
course  of  tuberculosis  of  acute  types  among  a  more  or  less 
completely  unprotected  native  population;  second,  to  the 
bad  hygiene  of  a  poor  and  ignorant  people  which  facilitates 
the  conversion  of  a  potentially  immunizing  tuberculous 
infection  into  tuberculous  disease  and  renders  the  course  of 
the  disease  more  acute. 

By  a  tropical  climate  is  generally  understood  the  hot  and 
moist  climate  of  the  tropical  sea-coast,  but  there  are  to  be 
found  in  the  tropics  climates  which  are  hot  and  dry  and 
those  which  are  relatively  cool  and  dry. 

As  we  have  already  seen,  in  the  tuberculized  tropical  sea- 
coast  city  pulmonary  tuberculosis  may  pursue  a  very 
chronic  course,  the  treatment  of  uncinariasis  may  almost 
transform  a  grave  situation  and  hygienic  betterments,  such 
as  an  improved  water  supply,  drainage  and  paving,  may 
result  in  an  appreciable  diminution  in  the  mortality  from 
tuberculosis  which  in  such  a  community  rises  and  falls  with 
the  general  mortality.  In  short,  the  situation  as  respects 
tuberculosis  in  such  a  city,  though  the  mortality  rate  may 
be  high,  does  not  differ  very  essentially  from  that  in  north- 

130 


TREATMENT  OF  TUBEECULOSIS  IN  THE  TROPICS  131 

ern  cities,  and  the  remedies,  improved  sanitation  and  better 
education,  are  the  same  as  have  effected  so  great  a  diminu- 
tion in  the  mortality  from  tuberculosis  in  more  highly- 
civilized  communities. 

These  considerations  are  of  importance  in  that  they  en- 
courage endeavor.  One  of  the  best  allies  of  the  tubercle 
bacillus  is  the  pessimist,  who  shrugs  his  shoulders  and  says 
that  the  conditions  are  hopelessly  bad.  It  is  uphill  work 
of  course,  especially  at  the  outset,  but  one  may  enter  upon 
the  treatment  of  tuberculosis  in  suitable  cases  among  the 
native  population  with  a  reasonable  hope  of  attaining  arrest 
or  even  cure  of  the  disease  in  a  fair  percentage  of  cases. 

Some  tropical  communities  are  attacking  the  tuberculosis 
problem.  Manila  is  the  tropical  city  best  known  to  the 
medical  officers  of  the  U.  S.  Army,  and  may  serve  as  an 
example.  It  appears  from  the  annual  report  of  the  Bureau 
of  Health  of  the  Philippine  Islands  for  1909-10  that  an 
average  of  1500  cases  of  tuberculosis  per  month  are  treated 
in  the  tuberculosis  dispensary  and  that  a  night  camp  has  been 
provided  where  30  cases  are  under  continuous  treatment, 
and  100  additional  cases  sleep  at  night  and  receive  instruc- 
tion. At  Baguio,  two  small  pavilions  having  been  con- 
structed for  tuberculous  cases,  the  demand  for  accommoda- 
tions became  so  great  that  three  others  have  been  built.  It 
is  stated  that  two  cures  have  already  resulted  and  that 
other  cases  are  rapidly  improving.  The  same  report  for 
1910-11  speaks  of  a  Carnival  Exhibition  organized  by  the 
Bureau  of  Health  at  which  pictures  are  displayed  with  a 
view  to  the  instruction  of  the  people  in  the  prevention  of 
tuberculosis.  In  1911-12  it  is  reported  that  the  systematic* 
campaign  against  tuberculosis  is  now  largely  in  the  hands 
of  the  Philippine  Anti-tuberculosis  Society,  which  was  first 
organized  in  1910,  also  that  the  Bureau  of  Health  has  set 


132  EPIDEMIOLOGY  OF  TUBERCULOSIS 

aside  two  wards  at  the  San  Lazaro  Hospital  for  the  treat- 
ment of  tuberculosis,  and  that  it  continues  to  maintain  its 
tuberculosis  camp  at  Baguio.  In  1913  the  Director  of 
Health  makes  the  statement  that  it  is  doubtful  whether  any 
country  has  ever  reaped  such  large  returns  in  improved 
health  and  reduced  mortality  with  so  small  an  expenditure 
of  funds  as  has  been  realized  in  the  Philippine  Islands.  The 
San  Juan  del  Monte  Sanatorium  at  Rizal,  which  is~  con- 
ducted by  the  Philippine  Anti-tuberculosis  Society,  is  first 
mentioned  in  the  1914  report,  from  which  publication  it 
appears  that  there  were  215  admissions  for  tuberculosis  at 
this  sanatorium  during  the  year  and  that  77  cases  were 
cured  or  apparently  arrested. 

At  the  naval  station  at  Guam  a  hospital  for  tuberculosis 
was  opened  in  1916.1  To  make  the  most  of  the  limited 
facilities  of  the  institution  it  is  proposed  to  keep  a  certain 
number  of  mild  or  incipient  cases  for  a  limited  time,  en- 
deavor to  build  them  up  by  rest  and  good  food  and  replace 
them  periodically  by  other  groups  of  patients. 

It  is,  of  course,  quite  possible  for  Europeans  to  become 
cured  of  tuberculosis  in  a  hot  and  moist  climate.  Robert 
Louis  Stevenson  is  a  conspicuous  example  of  such  cases. 
It  is  stated  that  the  pulmonary  tuberculosis  in  his  case 
was  found  to  be  arrested  and  fibrous  after  death  from 
another  cause.  Naturally,  however,  the  majority  of  the  class 
who  can  afford  the  expense  will  do  better  to  leave  the  sea- 
coast  for  some  elevated  region  with  drier  soil  and  air  and  a 
lower  temperature. 

Wherever  mountains  or  elevated  plateaus  are  accessible 
in  the  tropics  health  resorts  spring  up,  as  in  the  foothills 
of  the  Himalayas,  in  many  mountainous  islands,  such  as 

1  Annual  Report  of  the  Surgeon  General  of  the  Navy  for  1917. 


TREATMENT  OF  TUBERCULOSIS  IN  THE  TROPICS         133 

Reunion,  in  Ceylon,  Madagascar  and  Brazil.  The  table- 
lands of  the  Andes  in  South  America  are  in  high  repute  for 
the  climatic  treatment  of  tuberculosis.  Treutlin  states  that 
in  Bolivia  the  number  of  cases  of  pulmonary  tuberculosis 
seems  to  diminish  as  the  altitude  increases  and  cites  cases 
of  patients  coming  from  the  coast  in  bad  condition  who 
rapidly  recover  at  La  Paz.  He  recommends  this  town  for 
the  climatic  treatment  of  European  consumptives.1 

Morales2  says  that  miners  from  Chile  and  Peru  recover 
from  tuberculosis  in  the  dry  and  sunny  climate  of  La  Paz, 
but  that  cases  of  tuberculosis  among  the  natives  have  an 
extraordinarily  acute  and  deadly  character.  The  pretended 
immunity  of  the  inhabitants  of  high  altitudes  to  the  tubercle 
bacillus  is,  he  says,  only  an  illusion.  He  had  claimed  that 
the  tubercle  bacillus  was  capable  of  adaptation  and  that 
"  if  at  the  beginning  it  had  been  unable  to  live  at  this 
height  of  3629  metres,  as  was  eloquently  proved  by  the 
many  tuberculous  individuals  who  had  been  cured  there, 
it  was  very  possible  that  in  time  the  bacillus  would  accus- 
tom itself  to  the  new  medium  in  which  it  was  placed  and 
would  give  origin  to  a  new  strain  capable  of  living  in  cli- 
mates of  altitude,  while  its  congeners  from  the  coast  were 
perishing."  That  is  to  say,  the  reason  why  consumptives 
from  the  coast  improved  at  La  Paz  was  not  that  the  climate 
favored  an  increase  of  their  resistance,  but  that  the  micro- 
organisms which  they  brought  with  them  were  unable  to 
live  at  that  altitude!  Morales  thinks  that  he  has  proved 
this  point  because  cultures  of  tubercle  bacilli  sent  him  from 
Europe  did  not  infect  guinea  pigs  at  La  Paz,  though  the 
virus  from  indigenous  cases  was  very  deadly  for  these  ani- 

xDeutsch.  Archiv  fur  Klin.  Med.     Vol.  100,  1910,  p.  88. 

'Revista  de  Hig.  y  de  Tub.  Valencia.  Vol.  2,  1913.  Abstr.  Internat. 
Zentralblatt  fur  Tub.  Forschg.  Vol.  8,  p.  28.  See  also:  La  Semana 
Medioa,  Buenos  Aires.     Vol.  21,  1914,  p.  335. 


134  EPIDEMIOLOGY  OF   TUBERCULOSIS 

mals,  dismissing  with  scanty  consideration  the  obvious  ex- 
planation that  these  cultures  had  lost  their  pathogenicity 
during  the  long  journey. 

This  is  dangerous  doctrine,  for  the  natural  inference 
from  it  would  be  that  the  natives  of  high  altitudes  will  not 
be  readily  infected  by  contact  with  the  incoming  consump- 
tive. Furthermore,  if  the  tubercle  bacillus  of  the  coast  is 
"  capable  of  adaptation  "  to  the  high  altitudes,  there  is 
danger  of  the  inference  that  the  tuberculosis  of  the  new- 
comer will  in  time  assume  the  deadly  character  of  that  of 
the  native;  hence  a  new  dread  for  the  unfortunate  patient 
and  the  unnecessary  discrediting  of  a  climate  which  is  no 
doubt  a  valuable  one  for  the  treatment  of  tuberculosis. 

Vargas1  remarks  that  tuberculosis  has  invaded  the  high- 
lands of  Colombia,  which  a  few  years  ago  were  almost  free 
of  the  disease.  He  states  that  in  the  latter  part  of  the 
nineties  of  the  last  century  cases  of  pulmonary  tuberculo- 
sis were  shown  in  the  hospitals  of  Bogota  as  pathological 
rareties,  but  that  tuberculous  peritonitis  and  meningitis 
were  common,  the  course  of  tuberculosis  in  the  native  being 
characterized  by  rapid  cavity  formation,  miliary  forms  and 
meningitis.  Correspondingly  he  finds  that  while  tuberculosis 
acquired  elsewhere  is  remarkably  benefited  by  the  moun- 
tain climate,  the  tuberculous  native  is  little  helped  by  treat- 
ment. He  explains  this  as  due  to  the  fact  that  these 
patients  are  acclimated  and  therefore  do  not  receive  benefit 
from  the  climate.  Evidently,  however,  here  as  elsewhere, 
the  imperfectly  immunized  are  subject  to  the  acuter  types 
of  tuberculosis. 

Samanez2  states  that  Area  has  shown  that  during  the 
"  War  of  the  Pacific  "  tuberculosis  caused  a  greater  number 

Mour.  Am.  Med.  Assn.     Aug.  30,  1919. 

'La  Cronica  Medica  (Lima).     Vol.  26,  1909,  p.  393. 


TREATMENT  OF  TUBERCULOSIS  IN  THE  TROPICS         135 

of  deaths  among  the  Peruvian  soldiers  than  the  forces  of 
the  enemy.  According  to  Samanez  the  Peruvian  army  is 
almost  exclusively  composed  of  Indians.  In  the  period 
from  1904  to  1909  inclusive  nine  per  cent,  of  conscripts 
were  rejected  on  physical  examination  for  entrance  into  the 
army  and,  although  he  regards  the  examination  as  defective, 
33  per  cent,  of  the  rejections  were  for  tuberculosis.  The 
incidence  of  tuberculosis  is  worst  in  the  initial  period  of 
military  service.  From  1903  to  1909,  2071  soldiers  wer*a 
discharged  for  tuberculosis  out  of  a  total  of  3136  dis- 
charges, or  66  per  cent.  Of  these  850,  or  41.3  per  cent., 
had  service  of  less  than  six  months  and  507,  or  24.4  per 
cent.,  of  less  than  one  year.  In  the  year  1908,  222  soldiers 
were  discharged  for  tuberculosis  and  44  (or  29.6  per  1000) 
died  of  the  disease  in  the  garrison  of  Lima,  which  has  an 
average  monthly  strength  of  1485,  the  average  monthly  loss 
being  23,  of  which  number  19  were  discharged  and  four 
died,  a  ratio  of  monthly  losses  of  15.48  per  thousand  of 
strength.  The  mortality  from  tuberculosis  in  Lima  in 
1906  was  for  the  white  race  3.5,  black  5.7,  mestizo  5.9,  yel- 
low 28.0,  Indian  23.7  per  1000  inhabitants. 

The  high  percentage  of  rejections  for  tuberculosis  on  en- 
trance examinations  and  the  large  percentage  of  early  dis- 
charges for  this  diseease  show  that  the  Peruvian  conscript 
often  brings  his  tuberculosis  with  him  from  his  native 
mountains.  But  that  not  all  of  the  scattered  population, 
perhaps  not  all  of  the  isolated  mountain  villages,  have  been 
brought  into  contact  with  the  tubercle  bacillus  is  quite  pos- 
sible and,  if  it  is  the  case,  would  account  for  the  deadly 
nature  of  the  disease  among  the  natives  when  it  does  occur. 
Dryness  of  the  climate  and  a  clear  sky  not  only  favor  the 
dessication  of  the  tubercle  bacillus,  but  also  invite  to  an 


136  EPIDEMIOLOGY  OF  TUBERCULOSIS 

outdoor  life,  and  therefore  tend  to  prevent  the  spread  of 
tuberculous  infection.  We  have  already  seen,  however, 
that  the  dryness  of  the  South  African  climate  did  not  pro- 
tect the  natives  from  tuberculosis,  and  it  now  appears  from 
the  facts  just  cited  that  altitude  also  can  not  be  held  to 
exercise  any  protective  influence. 

The  central  plateau  of  Mexico  has  a  reputation  for  the 
cure  of  tuberculosis.  Mexican  medical  writers  claim  that 
tuberculosis  diminishes  regularly  in  percentage  of  incidence 
with  increasing  altitude.1  What  the  real  facts  are  could  be 
most  easily  determined  by  means  of  the  tuberculin  test. 
They  probably  do  not  differ  materially  from  those  obtained 
in  the  Andes.  It  is  important  not  to  ascribe  to  conditions 
of  climate  or  altitude  a  low  incidence  of  tuberculosis  due 
to  sparseness  of  population  and  infrequency  of  communi- 
cation with  more  highly  infected  centres.  The  conditions 
in  the  southern  part  of  the  Rocky  Mountain  plateau  of  the 
United  States  are  very  similar  from  a  climatic  point  of 
view  to  those  of  the  Mexican  highlands.  It  is  not  proposed 
to  consider  this  subject  here,  but  it  may  be  remarked  that 
while  residence  under  favorable  conditions  in  the  dry  cli-. 
mate  of  the  western  mountain  regions  of  the  United  States 
has  an  undoubtedly  beneficial  effect  upon  the  large  majority 
of  not  too  far  advanced  cases  of  tuberculosis,  no  one  would 
venture  to  make  for  it  such  claims  as  those  advanced  for 
the  highlands  of  Mexico  and  the  Andes. 

The  only  relatively  hot  and  dry  region  in  the  tropics 
which  could  be  considered  as  a  health  resort  is  the  northern 
half  of  Queensland,  a  colony  which  has  acquired  a  consider- 
able reputation  as  a  place  for  the  successful  treatment  of 

1  Des  diverse  Formes  de  la  Tuberculose  selon  les  differentes  Altitudes 
au  Mexique,  D.  Mejia,  Proc.  Eleventh  Intcrnat.  Med.  Congress.  Vol.  3, 
1894,  p.  117. 


TREATMENT  OF  TUBERCULOSIS  IN  THE  TROPICS         137 

tuberculosis  and  is  visited  by  many  consumptives  from 
abroad  in  search  of  health,  mainly  from  the  United  King- 
dom. 

It  seems  to  be  the  practice  in  tropical  colonies  to  repatri- 
ate at  once  cases  of  tuberculosis  that  develop  in  the  Euro- 
pean civil  and  military  officials  and  in  the  European  sol- 
diers. Something  is  to  be  said  for  the  at  least  temporary 
advantages  of  a  change  of  scene,  of  a  visit  to  one's  home 
and  of  the  stimulus  of  a  change  of  climate  even  though  the 
climate  relinquished  is  superior  to  that  of  the  individual's 
native  land.  It  is  evidently  imperative  to  send  away  a 
patient  of  any  status  who  firmly  believes  that  the  climate 
in  which  he  has  lived  is  fatal  for  his  disease.  This  idea, 
it  may  be  mentioned  in  passing,  is  derived  from  the  belief 
that  because  the  natives  die  of  an  acutely  fatal  tuberculosis 
the  European,  or  American,  who  has  tuberculosis  is  des- 
tined to  die  in  the  same  way,  the  idea,  in  other  words,  that 
the  type  of  the  disease  is  determined  by  the  geographical 
location  and  not,  as  is  the  fact,  by  the  degree  of  immunity. 
The  physician  is  sometimes  not  without  responsibility  for 
the  dissemination  of  such  notions. 

It  is  the  custom  in  the  United  States  Army  to  send  home 
as  speedily  as  possible  soldiers  in  whom  tuberculosis  has 
been  diagnosticated.  This  is  as  it  should  be,  for  once  that 
diagnosis  is  made  the  soldier  will  as  a  rule  be  useless  there- 
after for  tropical  service.  But  care  should  be  taken  not  to 
make  such  a  diagnosis  without  good  and  sufficient  reason. 
An  instance  has  been  known  in  the  Philippines  of  what 
seemed  to  be  a  veritable  epidemic  of  cases  with  sputa  posi- 
tive for  tubercle  bacilli.  Some  of  the  individuals  were  re- 
turned to  the  United  States  —  there  were,  it  is  believed, 
some  real  cases  of  tuberculosis  among  them.     With  regard 


138  EPIDEMIOLOGY   OF  TUBERCULOSIS 

to  the  others  a  legitimate  doubt  was  felt  on  account  of  their 
number  and  the  absence  of  other  signs  of  the  disease,  and 
nothing  was  done,  with  the  result  that  tuberculosis  did  not 
declare  itself.  In  such  cases  one  is  authorized  to  assume 
that  either  the  bacillus  found  was  not  the  tubercle  bacillus 
or  that  the  sputum  submitted  was  not  that  of  the  individual 
in  question.  It  is  not  at  all  uncommon,  however,  for  sol- 
diers who  leave  the  Philippines  with  sputum  positive  for 
tubercle  bacilli  and  with  the  other  signs  of  an  active  tuber- 
culosis to  arrive  at  Fort  Bayard  with  negative  sputum  and 
the  signs  of  an,  arrested  lesion.1  No  doubt  no  imposition 
had  been  practised  nor  any  fault  of  diagnosis  committed  in 
the  great  majority  of  such  cases.  The  fact  of  so  speedy  an 
arrest  is  to  be  explained  by  the  supposition  that  there  was 
but  a  slight  lapse  in  an  originally  high  immunity  from 
which  recovery  was  made  on  the  long  sea  voyage.  Such 
facts  constitute  a  manifest  confirmation  of  the  view  that 
tuberculosis  appearing  in  the  tropics  is  determined  as  to  its 
character  by  the  previous  experience  of  the  individual  as 
respects  contact  with  infection  quite  independently  of  the 
situation  of  the  locality  in  which  the  disease  became  mani- 
fest. It  may,  however,  be  possible  that  its  development  was 
in  some  way  ascribable  to  tropical  conditions  that  depress 
the  general  health.  In  other  words,  the  individual  might 
not  have  had  manifest  tuberculosis  if  he  had  not  been  in  the 
tropics,  but  the  form  and  severity  of  the  tuberculosis  was 
the  same  as  it  would  have  been  if  his  health  had  become 
equally  impaired  at  home. 

In  civil  practice,  tuberculosis  being  determined  to  be 
present  in  a  given  case,  the  first  question  that  arises  is  has 

1  The  General  Hospital  at  Fort  Bayard,  New  Mexico,  first  established  in 
1899,  was  until  the  late  war  the  only  sanatorium  devoted  to  the  treatment 
of  tuberculosis  in  the  U.  S.  army. 


TREATMENT  OF  TUBERCULOSIS  IN  THE  TROPICS  139 

the  patient  sufficient  means  to  permit  a  long  journey  and  a 
continued  residence  in  remote  parts  without  the  necessity 
of  exerting  himself?  If  not  he  will  fare  much  better  if  he 
applies  his  funds  to  secure  the  best  attainable  conditions  at 
home.  Unless  the  change  of  residence  will  undoubtedly 
result  in  "  physical  promotion  "  it  were  better  not  made. 
There  are  very  few  places  where  a  consumptive,  not  hope- 
lessly advanced  in  his  disease,  may  not  hope  for  at  least  a 
very  considerable  prolongation  of  life  provided  that  he  is 
wisely  instructed  and  faithfully  carries  out  his  instructions. 
The  physician  often  errs  in  assuming  more  knowledge  on 
the  part  of  the  patient  than  he  possesses.  The  minutiae 
should  be  inquired  into,  not  only  the  symptoms,  but  also 
the  ideas  of  the  patient  as  to  what  he  should  do  to  help  him- 
self. It  is  necessary  to  win  the  confidence  of  the  patient 
and  to  endeavor  to  dissipate  what  are  often  quite  unneces- 
sary apprehensions.  Some  have  unfortunately  been  faught 
that  swallowing  sputum  leads  inevitably  to  intestinal  tuber- 
culosis and  wear  themselves  out  in  anxious  endeavor  to  pre- 
vent this.  Others  may  have  the  idea  that  expectoration  is 
nature's  method  of  eliminating  poisons,  or  again  that  expec- 
toration not  immediately  brought  up  may  infect  new  parts 
of  the  lung  and  may  consequently  exhaust  themselves  in 
efforts  to  get  rid  of  mucus  at  the  first  indication  of  its  pres- 
ence. The  writer  has  repeatedly  seen  negro  patients  who 
cover  their  heads  with  the  bedclothes  when  desirous  of 
sleeping.  This  is  a  practically  universal  habit  in  the  negro 
race  not  only  in  the  United  States,  but  in  Africa.  It  is  said 
to  be  prevalent  also  in  some  races  of  India.  Of  course, 
nothing  could  be  more  prejudicial  to  a  treatment  of  which 
fresh  air  is  the  very  foundation. 

The  inhabitants  of  Mayotte,  one  of  the  islands  of  the 
Archipelago  of  Comores,  in  the  Pacific  Ocean,  have  appar- 


140  EPIDEMIOLOGY  OF  TUBERCULOSIS 

ently  evolved  a  method  of  their  own  for  treating  consume 
tion,  a  disease  which  is  much  feared.  According  to  Blin* 
tuberculosis  is  considered  curable  in  its  early  stages,  and  is> 
always  treated  as  follows:  At  first  the  patient  is  given 
the  most  absolute  rest  for  a  month  or  more.  During  this 
time  he  eats  every  day  a  dish  of  young  chicken,  melted  but- 
ter and  cardamon  seeds.  To  relieve  the  respiration  a  mix- 
ture of  flour  and  yolk  of  eggs  is  spread  upon  his  chest. 
Deep  inspiration  being  painful,  the  chest  is  constricted 
below  the  nipples  by  a  cloth  binder  so  as  to  prevent  full 
expansion.  Here  are  some  very  good  ideas,  absolute  rest, 
good  food  —  even  the  constriction  of  the  chest  has  respect- 
able medical  authority  for  its  support  —  but  mixed  with 
superstitious  or  unreasonable  practices,  such  as  the  external 
applications. 

The  author  does  not  report  as  to  the  success  of  this  treat- 
ment, but  one  can  hardly  expect  a  good  result  for  the  rea- 
son that  even  though  carried  out  in  a  manner  more  con- 
formable to  enlightened  practice  it  must  almost  necessarily 
be  begun  too  late.  That  is  the  evil  of  treatment  at  the 
hands  of  the  non-expert.  However  judicious  it  may  be,  it 
is  not  begun  until  the  indications  of  advanced  disease  are 
present.  In  the  tropics  as  elsewhere  the  desideratum  is  to 
detect  the  disease  in  its  incipiency  and  to  institute  treat- 
ment before  the  layman  can  make  the  diagnosis  or  the 
patient  become  conscious  of  failing  powers.  In  no  disease 
is  the  patient  more  dependent  upon  the  guidance  of  the 
skilled  physician  and  in  no  disease  has  the  physician 
greater  responsibility  for  early  detection  and  accurate  diag- 
nosis. Of  course  the  "  tripod  of  treatment "  in  the  tropics 
is  the  same  as  elsewhere  —  rest,  good  food  and  fresh  air. 
The  ability  to  be  out  of  doors  during  the  year  gives  a  cer- 

1  Ann.  d'Hyg.  et  de  Med.  Colon.     Vol.  7,  1904,  p.  335. 


TREATMENT  OF  TUBERCULOSIS  IN  THE  TROPICS  141 

tain  advantage  in  the  tropical  treatment  of  tuberculosis. 
On  the  other  hand,  the  heat  and  the  insects  make  for  rest- 
lessness. Repose  of  mind  is  as  important  as  repose  of 
body.  It  is  especially  important  to  reassure  the  patient  as 
to  the  possibility  of  improvement  in  view  of  the  widespread 
prevalence  of  the  idea  that  the  tropical  climate  forbids 
recovery.  One  who  believes  that  he  is  doomed  can  not  be 
expected  to  do  well.  Recounting  the  history  of  others  who 
have  recovered  helps  greatly.  After  cures  have  been  ef- 
fected it  is  easier  to  keep  hope  alive.  Of  course  benefit  from 
rest,  food  and  fresh  air  depends  upon  the  presence  of  an 
immunity.  It  is  futile  to  expect  a  manifest  primary  tuber- 
culosis to  be  benefited  by  such  means. 

One  word  as  to  the  responsibility  of  the  physician  who 
has  the  care  of  the  patient  in  the  interim,  while  he  awaits 
the  arrival  of  the  ship  or  before  he  goes  to  the  mountains. 
If  one  really  wishes  to  help  no  day  should  be  lost,  for  time 
is  precious.  The  patient  should  be  given  as  careful  instruc- 
tion and  be  restrained  as  sedulously  from  over-exertion  as 
would  be  the  case  if  he  were  to  remain  constantly  under 
treatment.  This  counsel  is  given  because  it  has  sometimes 
come  to  the  knowledge  of  the  writer  that  those  who  have 
temporarily  the  care  of  the  tuberculous  seem  to  take  their 
responsibilities  altogether  too  lightly.  One  of  the  great- 
est mistakes  in  the  treatment  of  tuberculosis  is  the  belief 
that  overdoing  or  other  neglect  of  precautions  can  be  atoned 
for  by  increased  care  in  the  future. 


CHAPTER  X 

TUBERCULOSIS   OF  THE  AMERICAN  NEGRO  AND   OF  THE 
AMERICAN  INDIAN 

It  is  commonly  said  that  the  negro  of  the  United  States 
was  free  from  tuberculosis  so  long  as  he  was  a  slave,  but 
became  tuberculous  to  an  alarming  extent  when  he  came 
into  contact  with  civilization.  For  one  who  has  perused 
the  preceding  pages  it  must  be  evident  that  this  statement 
is  incorrect.  Though  a  slave,  the  negro  was  not  out  of 
contact  with  civilization.  On  the  contrary  many  negro 
slaves  were  city-dwellers,  and  those  who  remained  upon  the 
plantations  were  many  of  them  in  the  closest  touch  with  the 
whites.  The  negro  children  played  with  the  white  chil- 
dren, the  men  were  coachmen,  jockeys,  valets,  barbers,  body 
servants  and  cooks,  the  women  cooks,  children's  nurses, 
waitresses,  chambermaids  and  washerwomen.  While  many 
of  the  hands  of  course  had  not  the  opportunity  to  fill  any 
positions  of  this  kind  there  can  be  no  doubt  that,  if  the 
negro  before  the  Civil  War  had  indeed  been  uninfected  with 
tuberculosis,  the  opportunities  for  at  least  occasional  in- 
fection were  such  that  epidemics  of  primary  tuberculosis 
must  have  resulted.  No  doubt  experiences  of  such  a  kind 
occurred  in  the  early  days  of  the  slave  traffic  but  long  be- 
fore the  recollection  of  any  one  now  living  the  negro  race 
must  have  become  thoroughly  enough  tuberculized  so  that 
the  serious  manifestations  of  tuberculous  disease  as  it  ap- 
pears in  unprotected  individuals  would  be  rare. 

The  earliest  accessible  records  are  those  of  the  health 
office  of  Charleston,  South  Carolina,  which  extend  from  the 

142 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN   143 

year  1822  to  the  present  time.  By  reference  to  the  chart 
compiled  from  these  records1  (Chart  No.  4)  it  is  seen  that 
the  mortality  from  consumption  for  the  period  1822  to  1830 
was  high,  but  nearly  equal  among  the  white  and  the  colored 
population,  and  that  while  it  declined  in  the  following  de- 
cades it  remained  nearly  equal.  From  1865  on  however 
the  difference  between  the  two  races  becomes  enormous. 
On  the  whole  the  white  death-rate  continues  to  decline  but 
that  of  the  negro  shoots  up  so  as  to  be  two  or  three  times 
as  great  as  that  of  the  whites,  and  there  is  no  longer  a 
parellelism  in  the  fluctuations  of  the  two  rates.  There  can 
be  no  question  that  before  the  Civil  War  the  negro  was  in 


MORTALITY  FROM  CONSUMPTION                          , 

IN  CHARLESTON,  S.  C.,    1822-1900 
RATE  PER  HUNDRED-THOUSAND 

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Chabt  No.  4. 


1  Tuberculosis  among  the  Negroes,  Thomas  J.  Jones.     Proc.  2d  Annual 
Meeting  National  Tuberculosis  Association.     1906,  p.  97. 


144  EPIDEMIOLOGY  OF  TUBERCULOSIS 

the  same  condition  as  respects  infection  with  tuberculosis 
as  the  whites,  in  other  words,  he  was  tuberculized  prac- 
tically to  the  same  degree  as  his  master;  the  almost  identi- 
cal mortality-rate  in  the  two  races  proves  this  beyond 
question.  The  frightful  mortality  after  his  emancipation 
must  therefore  be  explained  on  other  grounds  than  that  of 
the  primary  infection  of  a  completely  non-immunized  popu- 
lation. 

The  negroes  were  first  used  as  soldiers  in  the  Union 
army  in  1863. 1  Immediately  after  their  enlistment  during 
each  of  the  months  of  July,  August  and  September,  nearly 
one-half  of  the  command  is  reported  to  have  been  sick. 
From  this  highest  sick-rate  there  was  a  steady  decline  and 
the  health  of  the  negro  troops  improved  so  remarkably 
under  service  conditions  that  during  the  last  quarter  of  the 
year  ending  June  30,  1866,  their  sick-rate  was  somewhat 
less  than  that  of  the  white  troops.  Their  death-rate,  which 
was  high  at  first,  about  25  per  thousand  of  strength  dur- 
ing the  first  four  months  of  service,  declined  to  a  minimum 
of  3.18  per  1000  in  May,  1866,  but  was  always  higher  than 
that  of  the  white  troops.  This  improvement  of  untrained 
troops  under  conditions  of  active  service  in  time  of  war 
would  be  remarkable  enough  if  the  command  had  been  of 
essentially  the  same  composition  in  1866  as  it  was  in  1863. 
But  this  could  not  have  been  the  case  for  the  strength  of 
the  colored  forces  gradually  increased  from  2250  in  July, 
1863,  to  a  maximum  of  105,009  in  June,  1865.  There  must 
therefore  have  been  a  frequent  and  large  influx  of  recruits 
and  the  improvement  of  the  individual  soldiers  in  health 
must  have  been  more  rapid  in  many  instances  than  appears 
at  first  sight. 

1  Med.  and  Surg.  Hist,  of  the  War  of  the  Rebellion.    Part  3  Medical  Vol- 
ume, p.  24. 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN    145 

During  the  five  and  one-sixth  years  covered  by  the  statis- 
tics of  the  war  there  were  13,499  admissions  among  the 
white  troops  for  consumption,  with  5286  deaths,  being  at 
the  rate  of  6.1  and  2.2  per  1000  of  strength  respectively. 
Many  taken  sick  with  other  diseases  or  reported  at  first 
under  other  diagnoses  were  discharged  for  consumption. 
There  were  20,403  discharges  for  this  cause  among  the 
white  troops.  Among  the  colored  troops  the  cases  ad- 
mitted as  of  consumption  were  1331,  the  deaths  1211  or  7.2 
and  6.3  respectively  per  1000  strength.  There  were  592 
discharges  for  this  disease.  The  relatively  large  number 
of  deaths  was  due,  the  compiler  of  the  statistics  states,  to 
the  negroes'  homeless  condition  —  they  could  not  be  dis- 
charged in  order  to  go  home. 

After  the  Civil  War  the  annual  reports  of  the  Surgeon 
General  for  some  years  give  but  little  information  of  value 
concerning  the  relative  incidence  of  tuberculosis.  In  1867 
the  average  annual  strength  of  colored  troops  was  6561, 
their  admissions  to  sick  report  19,964,  each  man  on  an 
average  having  been  admitted  three  times  during  the  year, 
but  the  white  soldiers,  with  average  strength  of  41,104  and 
admissions  to  sick  report  numbering  122,181,  had  nearly 
as  high  rates. 

In  1884  the  statement  is  made  with  regard  to  consump- 
tion that  while  there  appears  to  have  been  no  material  dif- 
ference between  the  two  races  in  admission  rate,  the  com- 
bined rate  of  loss  by  deaths  and  discharges  has  been  some- 
what in  favor  of  the  white  troops.  In  1885  the  white  sol- 
diers numbered  21,944,  the  colored  2194 ;  the  ratio  per  1000 
of  strength  of  admissions  for  tuberculosis  is  given  as  3  for 
each  class. 

The  annual  report  of  1898  states  that  in  1896  the  ratios 
of  admission  and  non-effectiveness  were  considerably  lower 


146 


EPIDEMIOLOGY  OF  TUBERCULOSIS 


in  the  negroes  than  in  the  white  troops.  This  report  gives 
the  following  ratios  per  1000  of  strength  for  the  decade  1886- 
1895  for  tuberculosis  of  the  lungs.  White  soldiers,  admis- 
sions 2.93,  discharges  1.52,  deaths  .44;  colored  soldiers, 
admissions  3.93,  discharges  1.85,  deaths  .84;  Indians  (1891- 
1894) ,  admissions  25.39,  discharges  11.44,  deaths  7.04.  The 
annual  report  of  1905  remarks  for  the  year  1904  that  admis- 
sion and  discharge  rates  from  disease  for  white  troops  were 
in  excess  of  those  for  negroes  while  the  death  ratio  was  2.82 
per  1000  less  than  that  for  colored  troops.  Ratios  of  ad- 
mission for  tuberculosis  were,  whites  4.41,  colored  6.41. 

TABLE  No.  4 

Admissions  for  Pulmonary  Tuberculosis,  Enlisted  Men,  U.  S.   Troops, 
Phillippine  Islands,  by  Race 


Whites 

COLOBED 

Philippine  Scouts 

Yeah 

Mean 

Num- 

Ratio 

Mean 

Num- 

Ratio 

Mean 

Num- 

Ratio 

strength 

ber 

per  1000 

strength 

ber 

per  1000 

strength 

ber 

per  1000 

1908 

9711 

58 

5.97 

2260 

16 

7.08 

5085 

20 

3.84 

1909 

11685 

55 

4.71 

3159 

5 

4.31 

5539 

31 

5.77 

1910 

12277 

59 

4.81 

No  colored  troops  were 

5302 

15 

2.95 

1911 

12454 

46 

3.69 

in     the     Philippines     in 
1910  and  1911. 

5372 

11 

2.09 

1912 

11006 

45 

4.09 

1351 

12 

8.88 

5407 

26 

4.81 

1913 

9377 

56 

5.97 

1S11 

13 

7.18 

5096 

32 

6.28 

1914 

8375 

52 

6.21 

1878 

19 

10.12 

5020 

26 

5.18 

1915 

10493 

61 

5.81 

1341 

13 

9.69 

5505 

25 

4.54 

Admissions  to  sick  report  furnish  the  best  guide  to  the 
facts  as  to  tuberculosis  because  many  are  discharged  who 
die  at  a  later  time  of  the  disease,  so  that  the  deaths  in  ser- 
vice do  not  represent  the  whole  mortality,  but  in  part  the 
mortality  of  those  who  having  no  home  to  go  to  are  forced 
to  remain  in  the  service  to  die.  The  negroes  are  probably 
so  situated  in  a  larger  percentage  than  the  whites. 

Table  4  gives  the  ratios  of  admission  for  pulmonary 
tuberculosis  in  white  and  colored  soldiers  in  the  Philippines 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN   147 


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148  EPIDEMIOLOGY   OF  TUBERCULOSIS 

compared  with  the  ratio  of  the  Philippine  Scouts  for  the 
years  1908  to  1915,  inclusive.  Table  No.  5  gives  the  same 
data  for  white  and  colored  soldiers  in  continental  United 
States  and  in  Hawaii.  Both  tables  are  unfortunately  in- 
complete in  that  the  colored  troops  did  not  serve  in  the 
Philippines  in  1910  and  1911,  nor  in  Hawaii  until  1913. 
The  number  of  white  troops  considered  is  sufficient,  if  we 
except  Hawaii,  to  give  ratios  of  some  value.  The  ratios  of 
the  colored  troops  being  based  on  a  small  strength  fluctuate 
from  more  or  less  accidental  causes  so  that  they  can  only  be 
accepted  as  a  rough  approximation  in  a  general  way  to  the 
true  facts.  We  conclude  from  a  study  of  these  tables  that 
the  white  troops  have  more  tuberculosis  in  the  Philippines 
and  less  tuberculosis  in  Hawaii  than  in  the  United  States 
and  that  the  admission  rate  for  tuberculosis  of  the  colored 
troops  fluctuates  in  the  same  way  between  the  three  sta- 
tions, but  is  on  the  whole  always  higher  than  the  white 
troops,  while  the  ratios  of  the  Philippine  Scouts  are  lower 
than  those  of  both  white  and  colored  troops  in  the  Philip- 
pines. The  tuberculosis  death-rate  in  immunized  peoples 
rises  and  falls  in  a  general  way  with  the  general  death- 
rate.  We  may  therefore  not  only  obtain  an  idea  of  the 
comparative  healthfulness  in  general  of  the  different  sta- 
tions for  the  white  and  colored  troops  but  may  seek  also  a 
confirmation  of  the  above  facts  as  to  the  incidence  of  tuber- 
culosis by  considering  the  death  rates  of  the  two  classes  of 
troops.  For  the  white  troops  the  general  death-rate  per 
1000  of  strength  for  1904-1916  was  5.08  in  the  United 
States,  6.14  in  the  Philippines  and  3.03  in  Hawaii.  For 
colored  troops  it  was  8.51  in  the  United  States,  7.56  in  the 
Philippines  and  5.13  in  Hawaii,  these  figures  thus  pointing 
to  the  same  conclusions  as  were  reached  by  studying  the 
admission  ratios  for  tuberculosis.     But  the  numbers  of  the 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN    149 


colored  race  concerned  are  far  too  small  to  enable  definite 
conclusions  to  be  drawn  from  them  and  it  may  be  well  to 
consider  briefly  some  statistics  drawn  from  large  centres 
of  population. 

TABLE  No.  6 

Death    Rates    from    Pulmonary    Tt:berctxosis    is    the    District    of 
Columbia  pee  1000  is  five-year  periods   1880-1914  a^td 

FOR  THE  YEARS  1915,  1916  AND  1917. 


Period 


White 


Colored 


Combined 


1880—1884 

3.17 

6.96 

4.44 

1885—1889 

2.88 

7.05 

4.26 

1890—1894 

2.48 

5.29 

3.41 

1S95— 1899 

1.97 

4.68 

2.83 

1900—1904 

1.83 

4.92 

2.79 

1905—1909 

1.55 

4.94 

2.55 

1910—1914 

1.27 

4.53 

2.18 

1915 

1.14 

4.07 

1.95 

1916 

1.05 

3.74 

1.79 

1917 

.93 

3.12 

1.50 

Table  No.  6,  from  figures  furnished  by  the  Health  De- 
partment of  the  District  of  Columbia,  which  those  who  are 
best  able  to  judge  consider  very  accurate,  gives  the  death- 
rate  of  the  whites  and  of  the  colored  population  of  Wash- 
ington for  pulmonary  tuberculosis  for  a  considerable  period. 
From  this  table  it  appears  that  the  death-rate  of  the  col- 
ored people  is  always  much  larger  than  that  of  the  whites. 
But  the  death-rates  of  the  whites  fall  steadily  through  the 
successive  periods  or  years  for  which  the  figures  are  given. 
Those  of  the  negroes  on  the  whole  also  fall,  that  of  the  year 
1917  being  less  than  half  that  for  the  five  years  1880-1884. 
It  is  quite  evident  that  the  same  causes  (here  no  doubt 
hygienic  betterments)  are  in  operation  to  lesson  the  mor- 
tality rates  of  both  of  the  two  races. 

The  improvement  in  the  mortality  of  the  negroes  is  of 
especial  significance  on  account  of  the  very  bad  housing 


150  EPIDEMIOLOGY   OF  TUBERCULOSIS 

conditions  which  prevailed  after  the  Civil  War.  "  During 
the  War  the  slave  deserted  the  plantation  to  find  refuge 
and  liberty  in  the  District  of  Columbia,  the  only  spot  at 
that  time  in  the  United  States  that  offered  such  a  boon. 
The  rapid  influx  of  a  negro  population  estimated  to  have 
been  between  30,000  and  40,000  imperatively  demanded  im- 
mediate accommodation.  In  consequence  of  this  necessity 
hovels  of  every  description  arose  as  if  by  magic."1  This 
abnormal  growth  of  a  class  of  people  destitute  of  means 
and  education  and  ignorant  of  physical  laws  led  to  a  very 
high  mortality.  "  The  general  death-rate  in  1875  among 
the  white  population  was  21.04  against  42.86  per  1000  in 
the  colored."  Through  the  efforts  of  many  public-spirited 
citizens  an  investigation  was  made  of  the  insanitary  habi- 
tations mostly  inhabited  by  negroes,  which  were  hidden 
away  in  tortuous  alleys  in  the  middle  of  city  blocks  and  in 
other  out-of-the-way  places.  There  were  286  of  such 
"  alleys  "  on  which  lived  19,076  people.  The  health  condi- 
tions were  found  to  be  indescribably  bad.  This  inquiry  led 
to  the  condemnation  and  removal  of  the  worst  of  the  shan- 
ties and  hovels,  and  to  the  formation  of  the  Washington 
Sanitary  Improvement  Company,  which  erected  numerous 
sanitary  dwellings  for  the  use  of  the  poor,  both  white  and 
colored,  at  a  moderate  rental.  In  1907  the  company  owned 
200  houses,  occupied  by  400  families. 

In  connection  with  the  statistics  obtained  from  the  army 
serving  in  the  tropics  we  will  compare  the  general  mortal- 
ity and  the  mortality  from  pulmonary  tuberculosis  of  the 
two  races  in  six  large  cities  with  a  large  negro  population.2 

1  History  and  Development  of  the  Housing  Movement  in  the  city  of 
Washington,  D.  C.  G.  M.  Kober,  Washington  Sanitary  Improvement  Co., 
1907. 

'Negro  Population  in  the  U.  8.,  1790-1915,  Cummings.  Census  BureaAi, 
1918.  ' 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN   151 


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152  EPIDEMIOLOGY   OF  TUBERCULOSIS 

It  will  be  noted  in  this  table  that  the  general  mortality 
of  both  races  is  less  in  all  of  these  cities  in  1910  than  it 
was  in  1900  (except  in  the  negro  mortality  of  Chicago, 
where  the  unusually  low  rate  for  1900  is  somewhat  in- 
creased in  1910)  and  that  while  the  mortality  of  the  negro 
everywhere  considerably  exceeds  that  of  the  white  man  it 
bears  a  pretty  constant  relation  to  the  latter  and  is  evi- 
dently governed  by  the  same  laws.  It  also  appears  that 
New  Orleans,  with  its  subtropical  climate,  which  might  be 
expected  to  be  best  suited  to  a  race  which  originated  in 
the  tropics,  has  a  considerably  higher  general  mortality  for 
them  than  Boston  and  Chicago. 

Evidently  the  general  health  of  the  negro  improves  as  he 
goes  northward,  a  result  hardly  to  have  been  anticipated, 
which  is  probably  explained  by  freedom  from  the  diseases 
of  warm  countries,  malaria,  hookworm  and  the  like,  to 
which  the  negro,  as  for  the  most  part  a  common  laborer,  is 
more  exposed  on  the  average  than  the  white  man,  the  rate 
of  whose  mortality  is  practically  the  same  in  New  Orleans, 
Baltimore  and  Boston.  The  diminished  mortality  in  the 
north  can  not  be  explained  by  the  supposition  of  a  greater 
incidence  of  diarrhoeal  diseases  of  children  in  the  south 
for  the  percentage  of  negro  deaths  under  five  years  of  age 
is  lower  in  1910  and  in  1900  in  New  Orleans  than  in  any 
other  of  the  cities  in  the  table  except  Chicago.  Washing- 
ton has  the  lowest  general  mortality  rate  among  the  whites 
of  all  the  coast  cities,  in  both  censuses,  but  its  rate  does 
not  compare  favorably  with  that  of  Chicago  especially  in 
1900.  But  when  we  consider  the  death-rate  for  pulmonary 
tuberculosis  we  see  that  Washington  occupies  a  very  excep- 
tional position,  the  mortality  being  much  less  for  both  races 
than  that  of  any  of  the  other  cities.  This  low  rate  can 
hardly  be  due  to  climate,  for  the  rate  of  Baltimore,  but 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN   153 

about  forty  miles  distant,  with  practically  the  same  climatic 
conditions,  is  very  much  higher  in  both  races,  Boston  has  a 
higher  rate  than  New  Orleans  and  the  rates  of  New 
Orleans  and  Chicago  are  almost  identical  for  the  negro 
population.  The  spaciousness  of  Washington,  the  almost 
complete  absence  of  factories  and  the  large  admixture  in 
the  white  population  of  government  employes  who  are  free 
from  the  strains  of  the  competition  of  industry  and  busi- 
ness life  would  perhaps  account  for  the  low  rate  so  far  as 
the  white  race  is  concerned.  The  number  of  negroes  who 
are  government  employes,  while  much  smaller  than  that  of 
the  whites,  may  have  a  perceptible  eifect  in  the  reduction 
of  the  negro  death-rate  from  tuberculosis.  Nov/  while  the 
tuberculosis  death-rate  among  the  negroes  is  much  greater 
than  that  of  the  whites  everywhere  and  varies  in  general 
with  that  of  the  whites,  its  variations  are  smaller.  For 
example,  the  excess  of  the  Boston  rate  over  the  New  Orleans 
rate  is  greater  in  the  whites,  that  of  the  Boston  rate  over 
the  Washington  rate  is  very  much  greater  in  the  whites, 
the  rate  for  Boston  being  nearly  double  that  for  Washing- 
ton. 

It  will  be  unwise  to  attempt  to  draw  definite  conclusions 
from  fractional  variations  in  the  rates  of  the  individual 
cities.  We  may  say,  however,  that  it  would  appear  that 
northern  cities  are  more  favorable  to  longevity  than  south- 
ern cities  but  that  climate  has  little  if  anything  to  do  with 
the  comparative  mortality  from  pulmonary  tuberculosis  in 
large  cities.  Whatever  it  may  be  that  makes  the  negro 
peculiarly  susceptible  to  tuberculosis  operates  about  the 
same  way  in  city-life  everywhere. 

Because  of  his  color  the  negro  is  barred  from  much  pro- 
ductive industry.  As  he  therefore  can  not  compete  with 
the  whites  in  earning  capacity,  he  is  relegated  to  the  worst 


154  EPIDEMIOLOGY   OF  TUBERCULOSIS 

habitations  in  the  most  insalubrious  locations  and  to  ardu- 
ous or  poorly  paid  toil  everywhere,  the  peculiar  disadvan- 
tages under  which  he  labors  being  naturally  more  conspicu- 
ous in  their  effect  upon  health  in  the  crowded  centres  of 
population.  If  his  death-rate  from  pulmonary  tuberculo- 
sis could  be  compared  with  that  class  of , the  white  popula- 
tion which  lives  under  similar  economic  conditions,  it  is 
believed  that  there  would  be  found  to  be  little  difference. 
W.  H.  Baldwin1  says :  "  It  is  not  safe  to  assume  that  the 
difference  in  mortality  (between  the  whites  and  the  negroes 
from  pulmonary  tuberculosis  in  Washington)  is  due  to 
racial  susceptibility,  for  even  a  superficial  study  of  condi- 
tions discloses  bad  housing,  improper  food,  ignorance  of  the 
nature  of  disease,  and  lack  of  care  as  to  proper  medical 
treatment  among  the  colored  people  to  a  degree  that  raises 
the  question  whether  whites  subject  to  the  same  influences 
would  not  suffer  as  much  ".-  And  Cummings3  remarks  that 
it  is  not  improbable  that  among  certain  classes  in  urban 
communities  the  mortality  from  specific  causes  (tuberculo- 
sis, pneumonia  and  organic  heart  disease)  is  as  high  among 
whites  as  among  negroes,  but  that  no  adequate  data  are 
available  for  determining  mortality  rates  for  the  different 
social  or  economic  classes. 

1  Journal  of  the  Outdoor  Life.     September,  1907. 

2 "  Tuberculosis  is  known  to  attack  without  any  racial  preferences.  The 
small  differences  observed  among  the  various  divisions  of  mankind  in 
regard  to  their  liability  to  tuberculosis  are  traceable  to  social  and 
economic  causes.  Moreover  the  variations  displayed  by  the  different 
groups  of  white  humanity,  such  as  the  differences  in  the  incidence  of  the 
disease  between  city  and  country  dwellers,  rich  and  poor,  those  engaged 
in  indoor  and  outdoor  occupations,  persons  active  in  a  dusty  atmosphere 
as  compared  with  such  as  are  working  in  clean,  airy  shops  and  the  like, 
are  just  as  great,  often  greater  than  the  differences  observed  in  the  white, 
black,  red,  or  yellow  races".     Fishberg,  The  Jews,  p.  290. 

*  Loc.  cit. 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN    155 

According  to  Gebhardt,1  however,  the  statistics  of  Ham- 
burg are  compiled  to  show  the  relative  rates  for  disease  and 
death  as  compared  with  the  income  of  the  individual.  The 
figures  obtained  in  that  city  show  that  of  persons  with  an 
annual  income  of  over  2000  marks  ($500)  fifteen  per 
10,000  die  of  tuberculosis,  but  that  of  those  whose  income 
is  less  than  2000  marks  the  death-rate  is  at  least  40  per 
10,000.  If  we  may  apply  these  facts  to  the  negroes  of  the 
United  States  we  will  account  for  more  than  one-half  of 
their  mortality  from  tuberculosis  by  their  poverty  which  is 
harmful  in  part  by  reason  of  poor  and  insufficient  food,  but 
probably  much  more  on  account  of  bad  housing,  overcrowd- 
ing, etc.  In  Edinburgh,  Williamson2  found  that  the  num- 
ber of  cases  of  tuberculous  disease  increases  as  the  house 
accommodations  become  more  limited.  "  Pulmonary 
tuberculosis  is  a  disease  in  which  70  or  80  per  cent,  of  cases 
occur  in  houses  of  three  rooms  and  under;  the  number  of 
cases  is  larger  in  two-room  houses  than  in  three  and  larger 
in  houses  of  one  room  than  in  those  with  two."  In  study- 
ing such  statistics  we  should  not  fail  to  consider  that,  how- 
ever important  over-crowding  and  the  bad  ventilation 
which  almost  necessarily  results  may  be  for  the  develop- 
ment of  tuberculosis,  in  many  instances  the  resort  to  infe- 
rior accommodations  is  the  result,  not  the  cause,  of  the  dis- 
ease, that  is,  the  family  may  be  obliged  to  live  in  one  room 
because  the  father  is  unable  to  work  on  account  of  tubercu- 
losis. Such  cases  do  not,  however,  invalidate  the  general 
law  that  poverty  increases  the  incidence  of  tuberculous  dis- 
ease. Now  in  Edinburgh  the  people  who  inhabit  the  small- 
est tenements  are  for  the  most  part  Scotch,  and  while  some 

1  Cited  by  Boyd,  Annual  Report  of  the  Surgeon  General  of  the  Navy, 
1899,  p.  161. 

2  Brit.  Jour,  of  Tub.  Vol.  9,  1915,  p.  111.  Cited  by  Fishberg,  Pul- 
monary Tuberculosis,  2d  Edition,  1919,  p.  73. 


156  EPIDEMIOLOGY  OF   TUBERCULOSIS 

are  doubtless  poor  because  of  improvidence  or  dissipation 
on  the  whole  the  poorest  of  the  population  do  not  diffei 
very  materially  from  those  of  somewhat  larger  means  in 
education,  in  morality  and  in  their  views  of  life  in  general. 
But  in  the  negro  race,  while  there  are  many  who  are  sobei 
and  prudent,  of  excellent  character  and  in  every  way  good 
citizens,  it  is  nevertheless  true  that  the  majority  of  the 
population  are  extraordinarily  untrained,  improvident  and 
reckless ;  so  that  there  must  be  taken  into  account  not  onlj 
poverty  but  a  poverty  which  is  tenfold  worse  because  of  the 
failure  to  make  proper  use  of  the  scanty  means  at  hand. 
Viewed  in  this  light  the  negro's  susceptibility  to  tuberculo- 
sis is  very  considerably  due  to  his  unfortunate  social  posi- 
tion, his  improvidence  and  his  neglect  of  the  laws  of  health- 
ful living.  The  point  which  it  is  particularly  desired  to 
emphasize  here  is  that  the  negro  mortality  is  a  relatively 
stable  or  constant  mortality  in  the  sense  that  it  does  not 
differ  greatly  according  to  climate  or  location,  but  that,  as 
is  shown  by  Table  No.  6,  it  is  a  steadily  decreasing  mor- 
tality, which  is  influenced  by  the  same  factors  as  those  that 
control  the  tuberculosis  death-rate  among  the  white  popu- 
lation. In  other  words,  it  is  the  death-rate  of  a  tubercu- 
lized  population  just  as  is  that  of  the  whites. 

This  point  will  be  made  clearer  if  we  turn  for  a  moment 
to  a  race  in  which  immunity  against  tuberculous  infection 
from  previous  contact  with  the  virus  of  tuberculosis  has 
been  very  imperfect  or  absent.  General  Orders  No.  28. 
Headquarters  of  the  Army,  March  9th,  1891,  authorized 
the  recruitment  of  eight  troops  of  Indian  cavalry  and  nine- 
teen companies  of  Indian  infantry.  The  number  of  Indian 
soldiers  on  June  30, 1891,  was  417;  on  June  30th,  1892,  780; 
on  June  30th,  1893,  771;  on  June  30th,  1894,  547.  The 
Inspector  General,  in  his  report  to  the  Secretary  of  War 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN    157 

for  1893,  recommends  the  disbandment  of  the  Indian  mili- 
tary organizations,  and  in  1894  the  General  commanding 
the  Army  states  that  the  object  of  their  enlistment,  namely, 
to  ascertain  the  present  and  prospective  value  for  military 
purposes  of  the  several  Indian  tribes,  has  been  attained  and 
recommends  that  what  he  characterizes  as  "  the  experi- 
ment "  of  their  enlistment  should  be  given  up,  which  was 
done  in  that  year.  It  is  evident  that  the  experiment  was 
not  in  general  a  success  so  far  as  creating  serviceable  or- 
ganizations is  concerned,  but  it  does  not  appear  that  the 
conditions  of  health  among  the  Indian  soldiers  constituted 
one  of  the  reasons  for  their  disbandment.  But  the  ratios 
of  admission,  discharge  and  death  of  Indians  from  pulmo- 
nary tuberculosis  which  have  already  been  given  are  enor- 
mously greater  than  those  of  the  other  troops. 

In  his  report  for  1893  the  Surgeon  General  speaks  of 
"  the  increased  consumptive  tendency  to  which  Indians  are 
so  prone  when  they  give  up  their  wild  life  for  a  semi-civi- 
lized mode  of  living." 

In  1887  several  hundred  Apache  Indians,  among  whom 
were  comprised  some  women  and  children,  were  confined 
at  Mt.  Vernon  Barracks,  Alabama.  According  to  the  report 
of  the  Surgeon  General  for  1896  their  death-rate  in  the  first 
year,  1887-1888,  was  54.64  per  1000  and  during  the  second 
year  48.96,  but  it  ran  up  during  the  third  and  fourth  years 
to  109.69  and  142.84,  nearly  one-half  of  which  was  due  to 
tuberculous  disease.  At  this  time  great  improvement  was 
made  in  their  condition.  A  new  village  was  built  for  them 
and  they  were  placed  under  the  most  vigilant  sanitary 
supervision,  with  the  result  of  bringing  the  death-rate  in 
1891-92  down  to  109.75,  the  next  year  to  80.93  and  in  1893- 
94  to  98.36.  The  prisoners  were  transferred  to  Fort  Sill, 
Okla.,  in  October,  1894,  the  excessive  mortality  that  had 


158  EPIDEMIOLOGY  OF  TUBERCULOSIS 

prevailed  among  them  during  their  stay  in  Alabama  being 
one  of  the  chief  reasons  for  effecting  the  transfer.  Here 
they  were  assigned  land  and  led  a  freer  life.  At  the  end  of 
their  first  year  at  Fort  Sill  it  is  reported  that  their  condition 
was  much  improved,  but  that  the  death-rate  continued  high, 
83.05  per  1000,  yet  it  was  thought  that  a  large  part  of  the 
mortality  was  referable  to  infection  at  Mt.  Vernon  Bar- 
racks. Of  a  total  of  25  deaths,  17  were  due  to  tuberculous 
disease,  and  the  statement  is  made  that  but  for  the  tubercu- 
lous infection  the  death-rate  among  the  Indians  would  not 
be  high.  As  has  been  learned  by  personal  communication 
with  a  medical  officer  who  was  on  duty  at  Fort  Sill  during 
a  portion  of  1894,  glandular  affections  were  very  common 
among  these  Indians  and  the  deaths  were  chiefly  due  to  pul- 
monary tuberculosis. 

The  report  of  the  commanding  officer  of  Mt.  Vernon  Bar- 
racks for  1893  is  contained  in  the  report  of  the  Inspector 
General  of  the  Army  for  that  year.  From  this  report  it  ap- 
pears that  the  total  number  of  Apache  prisoners  in  1892  was 
343,  in  1893,  328.  This  officer  reports  a  remarkable  improve- 
ment in  the  mortality  of  all  diseases  except  consumption, 
which  he  says  is  the  prevailing  disease,  and  seems  to  pro- 
gress rapidly  and  fatally.  There  were,  he  states,  27  deaths 
from  tuberculosis  in  1892  and  17  deaths  in  1893,  which 
would  give  ratios  per  1000  of  78.7  for  1892  and  51.8  for 
1893. 

From  what  can  be  learned  of  these  Indians  at  Fort  Sill  it 
would  appear  that  some  progress  towards  tuberculization 
had  been  made  during  the  term  of  their  imprisonment. 
Unfortunately  no  data  as  to  post-mortem  findings  at  Mt. 
Vernon  Barracks  are  accessible,  but  the  high  mortality  and 
the  rapid  and  fatal  course  of  the  tuberculosis  show  clearly 
enough  that  the  Indians  had  not  had  that  protection  against 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN  159 

tuberculosis  which  long  contact  with  the  disease  has  con- 
ferred upon  the  civilized  whites  and  negroes.  Particularly 
significant  is  the  fact  that  the  highest  mortality  from  tuber- 
culosis occurred  not  during  the  first  year  of  imprisonment, 
but  in  the  third  and  fourth  years,  which  seems  to  point  un- 
mistakably to  infection  at  Mt.  Vernon  Barracks. 

In  1881  the  Wdter  had  medical  charge  for  about  three 
months  of  2800  Sioux  prisoners  of  war.  These  Indians  had 
surrendered  during  the  previous  winter,  after  a  long  war- 
fare. They  consisted  of  two  classes,  first  the  "  wild " 
Indian,  who  had  had  but  little  contact  with  the  whites. 
There  were  some  among  the  number  who  were  said  to  have 
but  recently  seen  a  white  man's  house  for  the  first  time. 
The  second  class  consisted  of  agency  Indians.  When  the 
warriors  of  the  first  class  fell  ill  it  was  because  they  had 
over-eaten  at  some  feast,  the  agency  Indians  were  more 
sickly.  Enlarged  cervical  glands  were  very  common;  oc- 
casionally a  child  died  with  swollen  abdomen,  the  disease 
probably  being  tuberculous  peritonitis.  The  pressure  of 
work  and  the  prejudices  and  fears  of  the  Indians  alike  for- 
bade a  medical  survey,  but  no  cases  of  pulmonary  tubercu- 
losis came  under  observation. 

Here  was  the  mingling  of  two  streams,  the  one  kept  free 
of  the  diseases  of  the  whites  by  the  enforced  separation  of 
continuous  warfare  (for  their  captivity  marked  the  close 
of  the  Sioux  wars,  save  for  the  abortive  outbreak  at  Pine 
Ridge) ,  the  other  contaminated  by  the  diseases  and  vices  of 
civilization.  The  writer  has  frequently  seen  the  scrofulous 
youths  from  the  Agency,  their  fleshless  limbs  fully  clad, 
looking  on  wistfully  at  the  dances  of  the  warriors  in  the 
summer  twilight,  where  braves,  stripped  to  the  breech- 
clout,  danced  on  the  grass  to  the  music  of  the  tom-tom, 
reproducing  in  pantomime  their  exploits  in  border  warfare 


160  EPIDEMIOLOGY   OF   TUBERCULOSIS 

or  in  horse-stealing,  and  revealing  in  many  instances  a  mag- 
nificent physique  and  a  boundless  vitality,  which  contrasted 
cruelly  with  the  listless  aspect  of  some  of  their  spectators. 
The  two  streams  became  one  when  the  Indians  aban- 
doned their  tipis  and  took  up  their  residence  in  houses 
under  the  guidance  of  agency  officials.  It  is  commonly 
said  that  the  wild  Indian  was  filthy  in  his  personal  habits. 
Certainly  no  care  was  exercised  to  guard  against  the  pollu- 
tion of  the  ground  about  his  habitations,  .but  when  the  con- 
tamination became  marked  the  village  was  moved,  so  that 
after  all  his  mode  of  life  was  not  insanitary  in  that  respect. 
But  when  the  Indians  took  up  their  residence  in  houses 
they  continued  the  practices  of  the  tipi,  although  no 
longer  able  to  move  away  from  their  infected  surroundings, 
&  natural  consequence  of  which  was  a  wide  dissemination 
of  tuberculosis.  The  opinion  derived  from  personal  obser- 
vation as  to  the  relatively  good  condition  of  the  Indian  tipi 
is  shared  in  by  Stefansson,  who  moreover  corroborates 
the  view  as  to  the  deadliness  of  house-life  for  the  unpro- 
tected Indian  in  his  remarks  concerning  the  Indians  of  the 
Mackenzie  Valley.  He  says :  "  The  Indian  tipi  is  not  only 
always  filled  with  fresh  air  but  it  never  becomes  filthy  be- 
cause it  is  moved  from  place  to  place  before  it  has  time  to 
become  so.  The  housekeeping  methods  which  are  satisfactory 
in  a  lodge  that  is  destined  to  stand  in  one  place  only  two  or 
three  weeks  at  a  time,  are  entirely  unsuited  for  the  log-cabin. 
Eventually  the  germs  of  tuberculosis  get  into  the  house  and 
obtain  lodging  in  it.  The  members  of  the  family  catch  the 
disease,  one  from  the  other,  and  when  the  family  has  been 
nearly  or  quite  exterminated  by  the  scourge,  another  family 
moves  in,  and  so  it  is  not  only  the  family  that  built  the  house 
that  suffers  but  there  passes  through  the  house  a  procession 
of  other  families  moving  from  the  wigwam  to  the  graveyard. 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN  161 

In  some  places  tuberculosis  has  made  a  nearly  clean  sweep  of 
the  population.  This  is  noticeably  true  at  Fort  Wrigley, 
where  we  were  told  that  only  nineteen  hunters  were  left  in 
all  the  territory  belonging  to  that  post."1  We  may  com- 
pare here  the  statement  of  Hirsch  that  on  the  Arabian  ana 
Abyssinian  coasts  consumption  among  the  Bedouins  is  met 
with  most  frequently  among  those  "  who  have  exchanged 
the  tent  for  a  stone  house."  Of  course  the  extermination 
of  whole  families  of  Indians  speaks  for  a  population  unpro- 
tected by  previous  contact  with  tuberculosis.  In  a 
thoroughly  tuberculizecl  population  the  mortality  from  an 
infected  dwelling  might  be  equally  high  among  the  young 
children,  but  many  adults  would  escape  manifest  disease. 
Those  of  the  adults  who  developed  clinical  tuberculosis 
under  such  conditions  would  owe  their  disease  to  depression 
of  the  vitality  from  bad  air  and  filthy  surroundings,  non- 
specific causes  of  the  tuberculous  exacerbation  which  would 
be  equally  operative  if  the  dwelling  were  not  infected  with 
tuberculosis.  Whether,  therefore,  the  residence  of  a  certain 
group  of  Indians  in  houses  is  to  be  regarded  as  subjecting 
them  to  the  danger  of  extermination  or  as  simply  leading 
to  a  regrettably  high  incidence  of  usually  more  or  less 
chronic  tuberculosis  depends  entirely  upon  the  degree  of 
their  previous  tuberculization.  According  to  Walker,1  in 
1896,  there  were  4893  Oglala  Sioux  (the  greater  number  of 
the  captives  already  referred  to  belonged  to  this  band)  of 
whom  741  were  tuberculous,  and  of  these  124  died  in  that 
year.  That  is,  148.7  per  1000  were  known  to  be  tubercu- 
lous and  the  annual  death-rate  from  tuberculosis  was  25.3 
per  1000.  It  is  reported  by  Brewer1  that  tuberculosis  was 
responsible  for  ninety-five  per  cent,  of  the  deaths  among 
the  Mojaves,  that  among  the  Pimas  and  Maricbpas  it  caused 

1  My  Life  with  the  Esquimaux,  p.  22. 

1  Cited  by  Hutchinson,  N.  Y.  Med.  Jour.    Vol.  86,  1907,  p.  624. 


162 


EPIDEMIOLOGY  OF  TUBERCULOSIS 


sixty-six  per  cent,  of  the  deaths,  and  that  it  is  very  preva- 
lent among  the  Hopis  and  Navajos.  But  on  the  other  hand 
the  report  from  another  Navajo  reservation  was  that 
tuberculosis  was  not  very  prevalent  but  was  always  fatal, 
and,  again,  among  the  Zunis  the  actual  amount  is  small  but 
the  mortality  is  one  hundred  per  cent.  Evidently,  then,  at 
least  at  the  time  of  this  report,  no  single  formula  expressed 
the  situation  of  the  American  Indian  as  respects  tuberculo- 
sis. Some  tribes  were  thoroughly  tuberculized,  others 
showed  the  characteristics  of  a  recent  acquaintance  with 
the  disease  in  its  high  fatality.  In  most  of  the  Indian 
tribes  it  would  probably  be  correct  to  say  that  tuberculiza- 
tion was  progressing  but  was  as  yet  not  complete. 

The  following  table  has  been  compiled  from  more  recent 
data  obtained  from  the  annual  report  for  1918  of  the  Com- 
missioner of  Indian  Affairs : 

TABLE  No.  8 

Death  Rates  from  All  Causes  and  frosi  Pulmonary  Tuberculosis  in 

Four  Indian  Tribes. 


Popu- 
lation 

Ratio  all  deaths 

Percentage  deaths 

Ratio  deaths  tub. 

Tribe 

to  population 

from    tuberculosis 

to  population 

per  1000 

in  all  deaths 

per  1000 

Zuni 

1815 

23.1 

4.7 

1.10 

Moqui 

4225 

15.4 

20. 

3.08 

San  Juan 

(Pueblo).. 

6500 

27.6 

22. 

6.15 

Pine  Ridge 

(Sioux).. . 

7340 

20.1 

38.5 

7.76 

We  compare  here  three  tribes  which  have  long  inhabited 
permanent  dwellings  with  one  (the  Sioux)  which  has  but 
recently  relinquished  the  tipi  for  the  house.  The  numbers 
concerned  are  too  small  to  furnish  ratios  of  much  value. 
So  far  as  they  go,  however,  they  show  the  Sioux  to  be  more 
severely  afflicted   with   tuberculosis   than   the  other  three 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN   163 

tribes.  Why  there  should  be  so  great  a  difference  between 
the  Zuni  and  the  other  two  southern  tribes,  especially  the 
Moqui,  the  writer  is  unable  to  say,  except  that  it  may  be 
due  to  a  lesser  degree  of  tuberculization  because  of  the  un- 
willingness of  the  Zuni  to  permit  close  association  with 
strangers.  The  incidence  of  tuberculosis  is  certainly  not 
to  be  explained  by  change  of  mode  of  life  in  the  southern 
tribes. 

The  report  of  the  Commissioner  for  1916  states  that  a 
large  percentage  of  the  Indian  mortality  from  tuberculosis 
occurs  among  children,  notes  that  the  appearance  of  tuber- 
culosis in  children  under  two  years  of  age  is  almost  inevit- 
ably the  precursor  of  a  fatal  issue,  and  goes  on  to  say  that 
strenuous  endeavors  are  being  put  forth  to  protect  the 
infants  by  a  campaign  of  popular  education,  "  baby-shows," 
visits  by  a  woman  supervisor,  the  issue  of  popular  illus- 
trated educational  pamphlets,  etc. 

Agency  or  school  hospitals  or  sanatoria  increased  from 
four  in  1888  to  87  in  1918,  with  a  total  capacity  of  2411 
patients.  During  1918,  17,441  patients  were  treated  at 
these  institutions.  These  facts,  which  are  undoubtedly  un- 
known to  the  greater  part  of  our  citizens  disclose  the  work- 
ing out  of  an  enlightened  policy  in  obscure  and  remote 
places  and  doubtless  under  many  difficulties  of  race  preju- 
dice and  superstitions  as  well  as  of  scanty  funds,  which  is 
exceedingly  gratifying.  This  work  is  already  beginning 
to  reap  a  reward,  for  Commissioner  Sells  had  the  pleasure 
of  stating  in  1917  that  "  last  year  for  the  first  time  in  more 
than  fifty  years  there  were  more  Indians  born  than  died 
from  every  cause  ".  If  this  good  work  continues  we  may 
no  longer  speak  of  the  Indian  as  a  vanishing  race.  It  is  to 
be  hoped  that  so  far  as  tuberculosis  is  concerned  the  worst 
is  over,  and  that  tuberculization  has  reached  the  stage  in 


164  EPIDEMIOLOGY  OF  TUBERCULOSIS 

which  mortality  is  not  out  of  proportion  to  morbidity  ax 
least  so  far  as  relates  to  the  majority  of  the  tribes  —  where 
conditions  differ  so  widely  it  would  be  rash  to  draw  too 
general  conclusions.  The  remark  that  the  mortality  from 
tuberculosis  is  largely  among  young  children  is  very  signifi- 
cant, for,  as  already  remarked,  in  primary  infections  the 
parents  would  be  carried  off  as  well.  When  children  die  of 
tuberculosis  and  the  older  members  of  the  family  survive 
we  think  in  general  of  faulty  hygiene  in  a  tuberculized 
population.  In  view  of  the  absolute  ignorance  of  the 
Indian  mother  as  to  the  proper  care  of  her  children  the 
work  of  education  of  the  Indian  Bureau  can  hardly  fail  to 
be  richly  rewarded  in  the  prevention  of  other  diseases  as 
well  as  of  tuberculosis. 

In  the  past  where  the  Indians  have  been  closely  aggre- 
gated, as  in  schools,  in  army  barracks,  or  in  prisons,  the 
result  has  too  often  been  a  prevalence  of  tuberculous  dis- 
ease which  only  fell  short  of  an  epidemic  because  not  all  the 
individuals  exposed  to  the  chance  of  infection  were  with- 
out a  previous  immunization.  The  Indian  is  often  spoken 
of  as  pining  like  a  caged  eagle  when  brought  into  civilized 
surroundings,  as  if  his  illness  were  of  the  mind  rather  than 
of  the  body.  Those  who  have  read  the  preceding  pages 
need  not  to  be  informed  that  the  reason  why  he  falls  a  prey 
to  tuberculosis  is  because  he  has  had  no  previous  vaccina- 
tion against  it. 

In  view  of  the  wide  prevalence  of  the  idea  that  the  high 
mortality  of  aboriginal  races  when  in  confinement  or  re- 
stricted to  narrow  limits  under  civilized  conditions  is  due 
to  psychical  causes  and  the  great  importance  of  a  correct 
understanding  of  this  matter  the  digression  will  be  par- 
doned if  a  brief  account  is  given  of  the  fate  of  the  natives 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN    165 

of  Tasmania.  Power,1  writing  in  1843,  says  that  it  was 
formerly  believed  that  pulmonary  consumption  did  not  exist 
in  Van  Diemen's  Land,  which  was  certainly  not  true  at 
the  time  of  his  writing,  whatever  may  have  been  the  case  for- 
merly. Consumption  in  that  climate  does  not  obtrude  itself 
on  the  attention  by  its  frequency,  he  says,  excepting  among 
the  aborigines,  in  whom  it  has  been  the  fatal  malady  by 
which  chiefly  their  numbers  have  been  reduced  to  the  mis- 
erable handful  which  now  remains  of  them.  Their  num- 
bers being  few,  they  were  restricted  to  one  small  island. 
"  Provisions,  clothing,  dwelling-places  and  proper  superin- 
tendents were  furnished,  but  to  a  wandering  race  accus- 
tomed to  rove  at  will,  to  procure  their  food  as  they  pleased 
and  to  live  where  and  how  they  liked,  the  confinement  to  a 
narrow  island  and  the  immediate  change  from  their  own 
free  and  unfettered  habits  to  the  more  constrained  and 
artificial  ones  of  civilized  life  proved  speedily  fatal.  They 
died  in  great  numbers  and  in  the  majority  of  cases  pulmo- 
nary consumption  was  the  disease  under  which  they  sank. 
An  improved  system  of  management  by  which  their  present 
mode  of  life  is  made  to  assimilate  more  closely  to  their  for- 
mer habits  has  of  late  years  been  introduced  and  it  is  satis- 
factory to  know  that  the  mortality  at  first  observed  has  dur- 
ing the  same  period  much  diminished."  But  the  improvement 
in  their  mode  of  life  came  too  late,  for  the  race  is  now  extinct. 
A  recent  writer,  commenting  upon  that  fact,  ascribes  their 
disappearance  to  the  fact  that  they  were  compelled  to  wear 
clothes!  Here  is  the  record  of  an  experiment  which  re- 
sulted even  more  disastrously  than  did  the  confinement  of 
the  Apache  prisoners  at  Mt.  Vernon  Barracks.  There 
could  be  no  more  striking  illustration  of  the  danger  which 
threatens  the  unimmunized  race  that  is  exposed  continu- 

1  Dublin  Jour.  Med.  Sci.     Vol.  23,  1843,  p.  83. 


166  EPIDEMIOLOGY  OF  TUBERCULOSIS 

ously  to  the  tuberculous  infection  that  contact  with  civi- 
lized life  seems  always  to  entail.  In  this  instance  the  num- 
bers of  the  natives  were  greatly  reduced  before  they  were 
restricted  to  a  single  island,  on  account  partly  of  their  con- 
stant feuds  with  the  whites.  Mental  depression  from  cap- 
tivity was  not  responsible,  therefore,  for  the  heaviest  losses 
nor  could  it  have  been  the  principal  cause  of  the  entire  dis- 
appearance of  a  group  in  which  there  must  have  been 
children  too  young  to  be  affected  by  the  loss  of  freedom. 

It  is  interesting  to  compare  the  experience  of  the  tropi 
cal  native  when  exposed  to  pneumonia  and  tuberculosis  in 
the  mines  of  South  Africa  with  that  of  the  negro  who  has 
been  in  close  contact  with  civilization.  Of  21,000  tropi- 
cal negroes  the  death-rate  from  pneumonia  in  1912  in  the 
Rand  Mines  was  26.30  per  1000;  of  190,000  non-tropical 
natives  it  was  8  per  1000.1  A  marked  preponderance  of 
deaths  from  pneumonia  was  observed  in  laborers  during 
their  first  months  of  employment.  Of  2031  deaths  from 
pneumonia  in  1912,  1199  deaths  occurred  among  those  who 
had  been  at  the  mines  less  than  six  months,  and  in  1913 
there  were  981  deaths  out  of  1668  among  the  same  class  of 
laborers.  From  the  report  of  the  Crown  Mines2  it  appears 
that  the  incidence  of  lobar  pneumonia  for  the  five  years 
1910-1914  was  38.45  per  1000  and  for  1916,  24.60  per  1000. 
The  incidence  of  pulmonary  tuberculosis  was  19.98  and 
26.83  respectively  for  the  two  periods,  so  that  evidently  the 
more  chronic  disease  is  overtaking  and  surpassing  the 
other. 

The  death  and  case-mortality  rates  for  tuberculosis  are 
not  indicative  of  the  incidence  of  that  disease  for  the  rea- 


1  Gorgas,  lor.  cit. 

'Report  of  the  Chief  Medical  Officer,  Crown  Mines,  1916. 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN  167 

son  that  of  late  years  hospital  trains  and  ships  have  been 
provided  to  return  the  tuberculous  to  their  homes.  Not- 
withstanding this  fact  the  case-mortality  percentage  for 
tuberculosis  other  than  pulmonary  in  the  period  1910-1914 
at  the  Crown  Mines  was  53.54  and  in  1916  40.00,  showing 
that  about  one-half  of  the  patients  who  suffer  from  this 
type  of  tuberculosis  were  not  able  to  leave  the  mines  after 
they  fell  sick  and  consequently  must  have  had  an  acute  and 
fatal  type  of  the  disease.  This  is  to  be  inferred  also  from 
the  frequency  with  which  organs  other  than  the  lungs  are 
involved,  this  fact,  as  has  already  been  pointed  out,  being 
characteristic  of  tuberculosis  of  the  non-immunized  or  but 
slightly  immunized  individual. 

On  account  of  the  great  fatality  of  pneumonia  and  tuber- 
culosis among  the  tropical  natives  and  of  the  danger  of  dis- 
semination within  the  tropics  of  tuberculosis  by  the  natives 
who  return  with  that  disease  to  their  homes,  the  Govern- 
ment ordered  that  the  recruiting  of  tropical  natives  from 
regions  north  of  latitude  22°  S.  should  cease  in  March, 
1913. 

Vaughan  and  Palmer,1  writing  on  communicable  diseases 
in  southern  camps,  make  the  following  remarks  as  to  the 
relative  prevalence  of  pneumonia :  "  In  the  south  under 
ordinary  conditions  of  civilian  life  pneumonia  is  relatively 
rare,  but  when  it  does  appear  is  highly  fatal,  and  is  highly 
fatal  because  it  is  rare."  Substitute  the  word  "  tuberculo- 
sis "  in  place  of  pneumonia  and  the  foregoing  statement 
would  apply  exactly  to  the  American  Indian  and  to  the 
tropical  negro.  But  as  thus  modified  it  does  not  apply  to 
the  negro  of  the  United  States.  The  tubercle  bacillus  was 
present  in  the  southern  camps,  without  doubt,  more  con- 
tour, of  Lab.  and  Clin.  Med.     Vol.  3,  1918,  p.  638. 


168  EPIDEMIOLOGY   OF  TUBERCULOSIS 

stantly  present  than  the  pneumococcus,  if  in  smaller  numbers, 
but  we  do  not  hear  of  epidemics  of  tuberculosis  among  the 
negroes  any  more  than  among  the  whites,  in  fact  the  inci- 
dence of  tuberculosis  has  been  small  in  both  races  and  is 
adequately  explained  by  the  supposition  that  what  did 
develop  resulted  from  the  activation  of  the  disease  that  the 
patients  brought  with  them  into  the  army. 

The  facts  adduced  as  to  the  tuberculosis  of  the  negro 
justify  the  following  conclusions:  the  negroes  as  a  race  in 
the  United  States  have  long  been  in  contact  with  the  virus 
of  tuberculosis.  They  are  probably  as  well  or  nearly  as 
well  tuberculized  as  the  white  race.  This  is  shown  by  the 
fact  that  when  they  were  slaves,  when  their  masters  gave 
regular  employment,  provided  food  and  to  some  extent 
looked  after  their  health,  their  tuberculosis  rates  differed 
little  from  those  of  the  whites.  When  their  emancipation 
thrust  them  unprepared  into  the  struggle  for  existence 
their  sufferings  and  errors  are  revealed  in  an  enor- 
mously increased  mortality  not  only  from  tuberculosis 
but  from  other  diseases.  But  becoming  soldiers,  the 
negroes  were  once  more  provided  for  and  compelled 
to  lead  regular  lives,  and  the  result  became  quickly 
apparent  in  rapid  reduction  of  their  morbidity  and  mortal- 
ity rates.  The  latter  has  never  for  long  reached  the  low 
level  of  the  white  soldier,  that  it  should  have  so  nearly  ap- 
proached that  level  in  so  brief  a  time  is  a  triumph  for  army 
sanitation  and  discipline.  The  contrast  between  the  negro 
soldier  and  the  Indian  soldier  is  most  instructive.  In  the 
one  case  induction  into  the  army  leads  to  rapid  reduction 
of  mortality  from  tuberculosis,  better  sanitation  enables 
the  acquired  immunity  to  assert  itself.  In  the  other  case 
the  poisons  of  civilization  overwhelm  a  vigorous  race  un- 
prepared by  previous  experience  to  resist  them.    The  Amer- 


TUBERCULOSIS  OF  THE  AMERICAN  NEGRO  AND  INDIAN      169 

ican  Indian  in  his  attitude  towards  tuberculosis  resembles 
the  African  negro,  the  American  negro  has  already  passed 
beyond  the  stage  of  primary  or  nearly  primary  tuberculous 
infection. 

When  stationed  in  the  Philippines  both  the  white  and  the 
negro  soldier  suffer  an  increase  in  tuberculosis  incidence. 
Neither  race  compares  favorably  with  the  Philippine 
scouts;  acclimatization  doubtless  plays  a  role  here.  Evi- 
dently Hawaii  is  a  particularly  favorable  climate  so  far  as 
tuberculosis  is  concerned.  Both  races  among  our  soldiers 
have  lower  rates  for  tuberculosis  than  they  have  at  home, 
on  an  island  the  natives  of  which  were  once  decimated  by 
tuberculosis1  —  a  fact  that  once  more  corroborates  the  law 
which  may  be  deduced  from  the  observations  already  re- 
corded: climatic  influences  are  negligible  factors  in  com- 
parison with  the  presence  or  absence  of  immunization 
against  tuberculosis. 

1 H.  M.  Lyman,  Hawaii  from  a  Health  Point  of  View,  Med.  Rec.    Vol.  54, 
1898,  p.  672. 


CHAPTER  XI 

EPIDEMICS  OF  TUBERCULOSIS 

As  has  been  already  remarked,  chronic  tuberculosis  of 
the  adult  type  is  unknown  in  the  first  years  of  life.  Tuber- 
culosis of  the  lungs  indeed  occurs  in  early  childhood  but  it 
is  of  an  acute  rather  than  of  a  chronic  type  and  is  usually 
associated  with  tuberculous  disease  of  other  organs.  Not 
until  the  sixth  year  is  reached  do  we  find  tuberculosis  of  the 
lungs  which  approximates  the  adult  type  and  even  at  that 
age  the  resemblance  is  to  the  rapidly  progressive  forms  of 
the  disease  rather  than  to  the  relatively  benign  chronic 
phthisis.  The  explanation  of  the  absence  of  the  chronic 
forms  at  an  early  age  is,  of  course,  that  the  power  to  re- 
strain the  multiplication  of  the  tubercle  bacillus  and  to  wall 
off  tuberculous  lesions  effectively  by  the  growth  of  connec- 
tive tissue  is  the  manifestation  of  a  degree  of  immunization 
which  is  only  attained  in  the  course  of  some  years  after 
infection.  As  we  have  already  remarked,  the  alternatives  for 
the  young  child  are  either  an  immunizing  infection  which 
does  not  result  in  manifest  disease,  or  at  most  shows  itself 
in  affections  of  bones,  joints,  glands  and  skin  of  a  chronic 
nature,  or  an  acute  and  fatal  tuberculosis.  The  same  is 
true  of  the  adult  if  his  manifest  tuberculosis  appears 
shortly  after  infection.  It  follows  then  that  primary  infec- 
tion cannot  cause  a  quickly  developing  chronic  pulmonary 
tuberculosis.  From  this  point  of  view  the  notion  that  a 
chronic  pulmonary  tuberculosis  which  has  recently  declared 
itself,  or  has  but  recently  been  detected,  can  be  traced  back 
to  opportunities  for  infection  within  a  few  weeks  or  months 

170 


EPIDEMICS  OF  TUBERCULOSIS  171 

seems  somewhat  naive.  We  have  but  to  contrast  the  usual 
clinical  course  of  such  cases  of  phthisis  with  the  terribly 
fatal  epidemics  of  primary  tuberculosis  already  described 
in  order  to  realize  that  primary  infection  can  not  at  once 
produce  the  former  type  of  the  disease. 

Many,  it  is  true,  speak  of  massive  infections  from  with- 
out and  conceive  of  the  childhood  tuberculosis  as  healed,  or 
of  a  superinfection  as  taking  place  though  the  primary  in- 
fection persists.  Now,  it  is  questionable  if  there  is  aify 
such  a  thing  as  a  massive  exogenous  infection  under  natural 
conditions,  that  the  childhood  infection  is  not  obsolete  is 
shown  plainly  enough  by  the  cutaneous  test  and  to  believe 
in  superinfection,  at  least  from  relatively  small  doses,  is  to 
run  counter  to  the  facts  of  other  chronic  infections  and  is, 
therefore,  forbidden  by  such  analogies,  as  well  as  very  dis- 
tinctly proved  to  be  impossible  by  experiments  on  animals 
much  less  resistant  than  man. 

Epidemics  of  tuberculosis  have  been  reported  occasion- 
ally in  the  literature.  The  cases  are  generally  found  to  be 
cases  of  more  or  less  chronic  tuberculosis  of  the  lungs,  the 
impression  as  to  the  epidemic  character  of  the  disease  hav- 
ing been  derived  from  the  fact  that  they  follow  one  another 
rapidly  in  time  or  occur  in  a  group  of  individuals  which 
have  been  in  some  way  closely  associated  with  one  another, 
as  inhabitants  of  the  same  tenement  or  workmen  in  the 
same  shop. 

Marfan1  reports  an  epidemic  of  pulmonary  tuberculosis 
in  an  office  in  Paris  in  which  twenty-two  employes,  most  of 
them  less  than  thirty  years  of  age,  worked  for  about  eight 
hours  a  day.  The  room  was  too  small,  containing  but  220 
cubic  metres  of  air.     The  ventilation  was  very  imperfect, 

1  Sem.  M6d.     Vol.  9,  1889,  p.  399. 


172  EPIDEMIOLOGY   OF  TUBERCULOSIS 

the  windows  opening  upon  courts  with  no  circulation  of  air. 
It  was  badly  lighted  —  the  sun  penetrating  it  but  little. 
The  floor  was  old,  uneven  and  full  of  cracks.  The  em- 
ployes were  minor  clerks  with  small  salary,  probably  badly 
lodged  and  fed.  Several  of  them  abused  spirituous  liquors. 
In  January,  1878,  a  clerk  who  had  been  employed  in  the 
room  for  twenty-four  years  died  of  phthisis.  He  is  sup- 
posed by  the  author  to  have  infected  the  room  by  spitting 
on  the  floor.  The  room  was  swept  in  the  morning  and  the 
clerks  often  arrived  in  time  to  breathe  the  dust  stirred  up 
by  the  sweeping.  Nothing  is  said  as  to  what  befell  the 
sweepers,  who  would  seem  to  have  been  much  more  endan- 
gered than  the  clerks.  But,  whatever  the  fate  of  the  former, 
during  the  period  beginning  November  27th,  1884  and  end- 
ing July  16th,  1889  thirteen  of  the  clerks  who  had  been 
employed  in  the  office  for  from  two  to  21  and  23  years  died 
in  succession  of  phthisis. 

The  case  has  been  reported  in  this  country  of  three  work- 
men employed  successively  at  the  same  lathe  who  developed 
tuberculosis  and  died  one  after  the  other.  In  another  in- 
stance several  teamsters  living  together  in  the  same  insani- 
tary lodging  house  developed  tuberculosis  almost  simulta- 
neously, or,  which  is  far  from  being  the  same  thing,  were 
discovered  at  about  the  same  time  to  have  chronic  pul- 
monary tuberculosis.  Perhaps  the  most  frequent  explana- 
tion of  such  occurrences  is  that  the  discovery  of  some  cases 
has  led  to  the  general  examination  of  a  group  that  had  pre- 
viously escaped  attention  and  thus  to  the  establishment  of 
the  fact  that  tuberculous  disease  existed  in  many  of  its 
members.  If  we  depend  upon  the  history  furnished  by  the 
patient  or  by  his  family  we  shall  often  be  led  to  believe  that 
the  disease  is  recent,  although  physical  examination  shows 
in  a  surprisingly  large  number  of  cases  that  even  well- 


EPIDEMICS  OF  TUBERCULOSIS  173 

marked  and  extensive  tuberculosis  may  exist  for  years 
without  apparently  exciting  any  suspicion  of  its  presence 
in  the  minds  of  intelligent  patients  and  of  their  friends. 
Sometimes  we  may  explain  such  events,  as  probably  in  the 
so-called  Paris  epidemic,  by  the  exposure  of  old  cases  of 
more  or  less  inactive  tuberculosis  to  the  same  conditions  of 
bad  hygiene.  And,  again,  the  bunching  of  cases  may  be 
due  simply  to  a  coincidence  that  may  be  expected  occasion- 
ally in  so  common  a  disease.  In  large  tuberculosis  hos- 
pitals it  is  not  unusual  to  see  a  group  of  far-advanced 
patients  carried  off  at  the  rate  of  one,  two  or  three  a  day 
when  the  conditions  of  weather  are  particularly  trying, 
while  at  other  periods  of  the  year  there  may  be  no  deaths 
for  weeks  at  a  time.  Naegeli  reports  an  instance  in  which 
a  dozen  or  more  deaths  from  miliary  tuberculosis  followed 
one  another  rapidly  in  the  same  hospital  after  which  no 
deaths  from  this  form  of  tuberculosis  occurred  for  many 
months.  Now  the  disease  in  these  cases  of  miliary  tuber- 
culosis was  undoubtedly  in  great  part  if  not  exclusively  sec- 
ondary to  old  lesions,  and  the  unusual  feature  was  the 
simultaneous  development  of  a  number  of  cases  of  a  rare 
type,  a  more  or  less  accidental  happening,  perhaps  influ- 
enced to  some  extent  by  depressing  meteorological  condi- 
tions, since  the  event  occurred  in  the  winter.  No  one  could 
properly  call  such  terminations  of  long-standing  disease  an 
epidemic.  It  is  equally  improper  to  call  recently  detected 
exacerbations  in  the  earlier  course  of  chronic  pulmonary 
tuberculosis  an  epidemic,  however  numerous  the  cases  and 
however  apparently  good  the  previous  health  of  the  indi- 
vidual concerned. 

It  is  interesting  to  compare  what  a  master  in  medicine 
calls  an  epidemic  of  tuberculosis  with  the  so-called  epi- 


174  EPIDEMIOLOGY   OF  TUBERCULOSIS 

demies  of  chronic  pulmonary  tuberculosis.  Virchow  says:1 
"  In  1849  I  reported  that  in  the  spring,  at  a  time  when 
typhus  generally  prevails,  intermittent  fever,  which  was 
widespread  in  Berlin  even  before  the  cholera,  developed 
more  and  more,  associated  with  large  spleen  tumors.  To 
this,  especially  at  the  end  of  April  and  the  beginning  of 
May,  acute  tuberculosis  was  associated.  Tuberculous  in- 
flammations of  the  pia  mater  in  children  and  adults,  of  the 
pleura,  the  pericardium  and  the  peritoneum,  fresh,  mostly 
isolated  (miliary)  tuberculosis  of  the  lungs,  spleen,  kid- 
neys, epididymis,  bones,  brain  glands  and  intestine  were 
more  frequently  than  I  ever  remember  to  have  seen  them. 
Generally  it  was  not  single  organs  that  were  attacked,  but 
a  large  number  of  tuberculous  organs  were  found  at  the 
same  time  in  the  same  individual,  as  is  usual  when  tubercu- 
losis appears  in  great  intensity.  Especially  to  be  men- 
tioned in  this  connection  is  tuberculosis  of  the  liver,  spleen, 
kidneys  and  serous  membranes.  Interesting  was  the  com- 
plete coincidence  of  this  epidemic  with  the  epidemic  of 
intermittent  fever  which  went  so  far  that  the  tuberculous 
had  intermittent  fever  and  the  patients  with  intermittent 
fever  upon  their  convalescence  entered  into  tuberculosis." 

The  preponderance  of  miliary  forms,  the  implication  of 
several  of  the  larger  viscera  in  the  same  case  and  the  tuber- 
culous serositis,  all  indicate  the  presence  of  acute  forms  of 
the  disease.  From  Virchow's  well-known  views  it  is  not 
to  be  expected  that  he  would  make  a  distinction  between 
primary  and  secondary  miliary  tuberculosis.  We  can  not 
determine  therefore  whether  or  not  adults  appeared  to  be 
attacked  by  primary  tuberculosis.  It  is  altogether  prob- 
able, of  course,  that  the  truly  primary  tuberculosis  was  con- 


1Ueber   die   Versehiedenheit   von   Phthise   und  Tuberkulose.   R.  Virchow, 
Verhandlungen  der  Pliysik.  Med.  Gesellscli.  in  Wiirzberg.     Vol.  3,  p.   104 


EPIDEMICS  OF  TUBERCULOSIS  175 

fined  to  the  children,  but  it  should  be  remarked  that  in 
some  rare  cases  of  old  tuberculous  infection  the  immunity 
is  so  completely  lost  that  forms  are  met  with  that  usually 
characterize  primary  tuberculosis.  The  peculiar  feature  of 
this  epidemic  is  the  fact  that  some  complication  led  to  such 
a  complete  breaking  down  of  the  immunity  against  tubercu- 
losis in  a  considerable  number  of  cases  nearly  at  the  same 
time.  Apparently  Virchow  connects  the  epidemic  with  in- 
termittent fever  as  its  cause.  It  would  seem,  therefore,  to 
be  an  instance  of  an  epidemic  infection  of  other  than  a 
tuberculous  nature  which  aggravated  to  a  remarkable  ex- 
tent existing  tuberculosis  (so  far  at  least  as  adults  were 
concerned)  rather  than  an  epidemic  of  tuberculosis  in  the 
ordinary  sense  of  the  word. 

At  a  western  military  post  of  the  United  States  Army  it 
was  believed  in  1912  that  an  epidemic  of  tuberculosis  was 
prevailing.  Many  of  the  soldiers  were  affected  with  an  acute 
bronchitis,  with  abundant  purulent  expectoration,  and  in 
some  cases  with  well-marked  fever.  None  of  the  patients 
were,  however,  seriously  ill,  and  in  none  of  them  were  there 
any  discoverable  parenchymatous  pulmonary  lesions.  The 
disease  had  begun  in  a  certain  barrack  and  there  the  num- 
ber of  cases  was  greater  and  the  type  of  the  disease  more 
severe  than  elsewhere.  There  seemed  to  be  good  grounds 
therefore  for  considering  it  infectious.  It  was  the  opinion 
of  the  medical  officers  that  the  disease  was  spreading 
rapidly  and  ineffectual  attempts  were  made  to  check  it  by 
the  disinfection  of  barracks,  bedding,  etc.  Now,  as 
the  writer  convinced  himself  by  personal  observation,  there 
was  no  reason  to  consider  the  disease  (which  was  really  a 
bronchitis  due  to  streptococcus  infection)  to  be  tuberculosis 
from  any  of  the  findings  of  physical  diagnosis.  But  as  an 
epidemiological  problem  could  not  the  nature  of  the  affec- 


176  EPIDEMIOLOGY  OF  TUBERCULOSIS 

tion  have  been  determined,  as  respects  the  presence  of 
tuberculosis,  independently  of  the  physical  signs  in  the  in- 
dividual cases  ?  The  answer  is  undoubtedly  in  the  affirma- 
tive. We  had  here  an  infection  which  was  spreading 
rapidly  and  to  which  those  who  had  been  exposed  offered 
little  resistance.  Infection  was  rapidly  succeeded  by  mani- 
fest disease.  Under  the  circumstances  if  the  infection  was 
tuberculous  the  disease  must  have  been  primary  tuberculo- 
sis in  which  case  its  course  must  have  been  quickly  fatal. 
But,  as  a  matter  of  fact,  no  deaths  occurred;  the  patients 
for  the  most  part  were  not  even  confined  to  their  beds. 

On  the  supposition  that  the  disease  was  tuberculosis  we 
have  therefore  two  series  of  facts  that  are  absolutely  incom- 
patible ;  on  the  one  hand,  a  dangerous  infection  that  spread 
rapidly  and  became  manifest  disease  at  once,  on  the  other, 
fairly  good  physical  condition,  a  benign  course  and  obscure 
physical  signs.  The  epidemic,  if  it  was  of  a  tuberculous 
nature  at  all,  was  therefore  an  epidemic  of  chronic  rela- 
tively benign  pulmonary  tuberculosis,  which  is  impossible. 

Primary  tuberculosis  alone  can  occur  in  epidemic  form. 


CHAPTER  XII 

SOME  PRACTICAL  CONSIDERATIONS 

The  foregoing  discussion  will  have  been  made  in  vain  if 
it  has  not  impressed  the  reader  with  an  increased  sense  of 
responsibility  as  to  the  care  of  the  uninfected. 

The  group  of  the  uninfected  which  we  always  have  with 
us  is  that  of  the  young  children.  It  is  they  who  are  in 
especial  danger  of  infection,  and  it  is  they  in  whom  the 
infection  appears  in  its  most  deadly  forms.  Yet  singularly 
enough  in  the  popular  teachings  stress  is  laid  upon  the 
danger  of  adult  infection,  or  reinfection,  which  are  prac- 
tically non-existent  and  comparatively  little  is  said  as  to 
the  protection  of  the  infant.  The  importance  of  separat- 
ing the  child  from  the  open  case  of  tuberculosis  has  already 
been  referred  to,  likewise  the  possibility,  if  not  the  great 
probability,  that  the  apparently  healthy  mother  or  nurse 
is  at  times  a  "  bacillus  excreter  ".  The  old  women  nurses, 
with  their  chronic  coughte  and  their  inveterate  tendency  to 
taste  the  baby's  food  and  to  put  their  possibly  infected  fin- 
gers into  its  mouth  on  every  occasion  are  a  particularlyj 
dangerous  class.  It  is  said  that  after  two  infant  children 
of  a  royal  house  had  died  of  miliary  tuberculosis  it  was  dis- 
covered that  their  old  nurse  had  a  tuberculous  infection  of 
the  maxillary  sinus  with  a  fistulous  opening  into  the  mouth 
through  which  mucus  laden  with  tubercle  bacilli  frequently 
passed. 

It  would  be  easy  to  create  a  state  of  mind  bordering 
upon  panic  if  the  mothers  should  conceive  the  idea  that  they 
are  in  danger  of  infecting  their  children;  the  instructions 

177 


178  EPIDEMIOLOGY   OF  TUBERCULOSIS 

which  they  receive  should  therefore  be  judiciously  conser- 
vative. The  best  rules  are  those  of  politeness  which  in  part 
are  founded  on  some  instinctive  desire  to  avoid  a  too  inti- 
mate and  possibly  dangerous  contact  with  others.  That 
the  child  is  too  young  to  object  is  not  a  reason  why  it  should 
be  kissed  indiscriminatingly  upon  the  mouth,  or  why  fin- 
gers should  be  rubbed  upon  its  gums  without  previous 
sterilization.  If  the  gums  are  sore  from  protruding  teeth 
that  is  a  most  excellent  reason  for  abstaining  from  such  a 
practice,  for  infection  is  undoubtedly  more  easily  acquired 
then  than  at  any  other  time  in  the  history  of  the  individual. 
It  is  a  good  rule  to  allow  no  one,  the  doctor  included,  to 
insert  a  finger  into  the  mouth  of  the  infant  except  after 
proper  sterilization.  Mothers  may  well  be  instructed  not 
to  feed  the  child  with  a  spoon  which  they  themselves  have 
used,  nor  to  give  it  a  bone  from  which  they  have  gnawed 
the  meat,  nor  to  return  to  it  articles  wet  with  its  saliva 
which  it  has  dropped  upon  the  floor,  to  be,  of  course,  imme- 
diately returned  to  its  mouth.  The  so-called  "  dirty  age  " 
when  the  child  puts  everything  that  it  can  reach  into  its 
mouth  is  the  most  dangerous  time  in  the  child's  life  so  far 
as  infection  with  tuberculosis  is  concerned.  Scrupulous 
cleanliness  should  be  inculcated  with  at  the  same  time  an 
avoidance  of  any  attempt  to  attain  an  impossible  condition 
of  asepsis.  Of  course,  no  nurse  should  be  tolerated  with 
regard  to  whom  there  is  any  suspicion  of  active  tuberculo- 
sis. A  physical  examination  by  an  expert  is  the  only  way 
in  which  this  possibility  can  be  excluded  with  any  approach 
to  certainty. 

Pollak1  of  Vienna  found  that  children  over  four  years  of 
age  did  not  appear  to  be  unfavorably  affected  in  any  way 

'Beitr.  z.  Klinik  d.  Tub.    VoL  19,  p.  469.    See  also:    Ibid,  p.  393. 


SOME  PRACTICAL  CONSIDERATIONS  179 

by  the  entrance  of  a  tuberculous  individual  into  the  family 
circle,  while  those  of  lesser  years  grew  up  more  delicate 
than  their  older  brothers  and  sisters. 

Bergmann1  had  very  similar  results  in  Sweden.  He 
found  that  of  children  of  tuberculous  families  the  mortality 
from  tuberculosis  reaches  12  per  cent,  in  those  exposed  to 
infection  in  the  first  year  of  life  and  11.8  per  cent,  in  those 
exposed  during  the  first  four  years,  but  no  children  first 
exposed  after  the  fourth  year  have  died  of  tuberculosis 
among  his  cases  and  no  cases  of  tuberculosis  have  devel- 
oped from  exposure  after  the  seventh  year. 

Fishberg2  found  that  in  the  fifth  to  sixth  year  of  life 
children  in  overcrowded  tenement  houses  in  New  York 
reacted  positively  in  65.26  per  cent,  if  their  parents  were 
tuberculous,  and  in  50  per  cent,  if  their  parents  were  not 
thus  affected,  but  thinks  that  the  proportion  of  "  reactors  " 
is  about  the  same  for  the  two  groups  from  the  seventh  to 
the  fourteenth  year.  The  opportunities  for  infection 
under  the  conditions  of  tenement  life  are  evidently  so 
numerous  that  when  the  child  is  old  enough  to  move  about 
freely  he  is  certain  to  become  infected  before  long.  The 
especial  danger  of  infection  from  tuberculous  members  of 
the  family,  then,  lies  rather  in  the  probable  large  size  and 
frequency  of  the  infecting  doses  than  in  much  increased 
probability  of  infection  per  se.  We  have  seen  that  the  con- 
ditions as  to  tuberculous  infection  were  so  bad  at  Lipp- 
springe  in  the  early  part  of  the  nineteenth  century  that  the 
arrival  of  consumptives  in  large  numbers  seemed  to  make 
no  difference  as  to  the  infection  of  the  population. 

xDie  Gefahrdung  von  Kindern  duroh  tuberkulose  Ansteckung.  Disserta- 
tion. Upsala,  1918.  Abstr.  Internat.  Zentralblatt  f.  Tub.  forsch.  Vol.  12, 
No.  7,  July  31,  1918. 

2  Arch.  Pediat.     Jan.,  1915. 


180  EPIDEMIOLOGY  OF  TUBERCULOSIS 

At  present  the  role  of  the  bovine  tubercle  bacillus  is  dis- 
tinctly subordinate  to  that  of  the  human  bacillus  in  the 
infections  of  man,  even  in  our  civilivation,  and  in  many 
countries  in  which  cattle  are  rare  and  milk  and  its  products 
do  not  form  a  part  of  the  daily  food  of  the  inhabitants,  it 
has  practically  nothing  to  do  with  the  dissemination  of 
tuberculosis.  Now,  if  in  countries  in  which  milk  is  not 
produced  all  scattering  of  human  tubercle  bacilli  could  in 
some  miraculous  way  be  stopped,  tuberculosis  would  soon 
cease  to  exist.  But  how  would  it  be  in  a  country  of  milk- 
drinkers  like  our  own?  In  the  United  States  no  less  than 
in  countries  such  as  China,  Japan  and  Africa  in  which  milk 
does  not  constitute  a  part  of  the  food,  the  opportunities  for 
infection  with  the  human  tubercle  bacillus  are  so  great  that 
nearly  every  one  becomes  infected  with  the  human  type 
before  the  bovine  bacillus  is  ingested.  Hence  an  immuni- 
zation which  prevents  the  bovine  infection  from  taking 
hold.  The  bovine  bacilli,  though  unable  to  excite  a  progres- 
sive infection,  may  nevertheless  succeed  in  reaching  the 
lymph-glands  and  may  be  discovered  there  by  biological 
tests.  If  manifest  tuberculosis  of  the  human  type  is  pres- 
ent, bovine  bacilli  are  usually  to  be  regarded  as  more  or  less 
harmless  intruders  in  an  organism  that  is  immunized 
against  them  by  antecedent  infection.  In  the  rare  cases  in 
which  it  is  found  that  one  organ  contains  bacilli  of  the 
human,  another  those  of  the  bovine  type,  so  that  the  case 
presents  itself  as  a  true  mixed  infection,  the  explanation 
undoubtedly  is  that  the  infection  with  one  type  was  suc- 
ceeded so  rapidly  by  contact  with  the  other  that  immuniza- 
tion had  not  become  sufficiently  advanced  to  forbid  super- 
infection. In  Weber's  cases  of  infection  through  contami- 
nated milk  it  was  sometimes  found  that  of  a  family  of  chil- 
dren who  had  been  equally  exposed  only  the  youngest  gave 


SOME  PRACTICAL  CONSIDERATIONS  181 

evidence  of  infection.1  Manifestly,  here  the  correct  expla- 
nation is  that  the  older  children  had  become  immunized 
against  a  new  infection  by  previous  contact  with  the  human 
tubercle  bacillus.  In  general,  bovine  tuberculosis  is  a  dis- 
ease of  childhood  and  the  fact  that  it  is  relatively  rare  in  a 
nation  of  milk-drinkers  is  one  of  the  best  proofs  that  an 
immunity  against  the  bovine  type  is  regularly  obtained 
through  early  infection  with  the  human  tubercle  bacillus. 
But  supposing  that  by  herculean  efforts  we  had  attained  the 
impossible,  that  we  had  totally  extirpated  the  human 
tubercle  bacillus;  what  would  be  the  result?  If  the  fore- 
going reasoning  is  correct,  evidently  what  we  should  have 
to  expect  would  be  that  our  children,  instead  of  becoming 
infected  with  the  human  type,  would  receive  infections  from 
the  bovine  bacillus.  It  is  an  Utopian  dream,  in  the  judg- 
ment of  the  writer,  to  hope  that  the  tuberculous  infection 
of  cattle  will  ever  be  totally  eradicated.  But  if  this  is  not 
done,  given  the  disappearance  of  the  typus  humanus,  im- 
mediately bovine  tuberculosis  rears  its  horrid  head  prob- 
ably as  formidable  a  menace  as  tuberculosis  of  the  human 
type  has  ever  been !  The  only  way  to  prevent  this  would 
be  either  to  give  up  the  cow  or  to  resort  to  a  more  conscien- 
tious sterilization  of  all  milk,  not  only  as  a  beverage  but  as 
used  in  butter  and  cheese  in  all  its  forms,  than  could  ever 
be  realized  on  a  large  scale.  The  outlook  is  therefore 
doubly  hopeless.  Civilized  man  can  never  escape  the  dan- 
gers of  infection  with  the  tubercle  bacillus.  But  if  we  did 
escape  the  dangers  of  infection,  we  should  also  lose  the 
benefits  of  tuberculization.  Supposing  that  with  extraor- 
dinary energy  and  sagacity  we  banish  all  tuberculosis  from 
our  town  and  rear  an  absolutely  uninfected  group  of  chil- 

1  Tub.  Arb.  aus  d.  Kais.  Ges.  Amte.     Heft  10,  1910,  p.  29. 


182  EPIDEMIOLOGY  OF  TUBERCULOSIS 

dren.  Having  passed  a  childhood  under  the  irksome  re- 
strictions that  would  be  necessary,  the  time  must  come 
when  they  shall  be  permitted  to  enter  the  outside  world,  for 
the  fear  of  disease  can  not  remain  the  paramount  considera- 
tion during  life.  As  soon  as,  now  adults  or  adolescents, 
they  leave  the  sheltering  confines  of  their  native  town,  they 
will  be  exposed  to  the  dangers  of  primary  tuberculous  in- 
fection and  that  at  an  age  when  the  world  beckons  most 
invitingly  and  when  prudence  is  least  developed!  In  fact 
they  would  be  in  a  hardly  less  dangerous  situation  than  the 
tropical  native  when  he  first  enters  a  civilized  community, 
Prophylaxis  has  simply  resulted  in  exchanging  the  danger 
of  a  chronic  and  usually  relatively  benign  infection  for  the 
danger  of  an  acutely  fatal  infection. 

At  the  time  when  control  of  expectoration  first  bulked  so 
large  in  the  eyes  of  the  sanitarian  the  community  was 
divided  in  his  thought  into  two  classes  as  respects  tuber- 
culosis, the  tuberculous  and  the  healthy.  Very  slowly  and 
reluctantly  since  that  time  the  knowledge  of  the  true  facts 
has  been  acquired  and  still  more  slowly  and  reluctantly  has 
it  been  disseminated  —  in  fact  it  still  seems  incredible  to 
many  that  tuberculization  should  be  so  well-nigh  universal 
as  it  undoubtedly  is.  If  it  seems  likewise  a  terrible  fact 
that  conclusion  is  erroneous.  The  error  lies  in  the  assump- 
tion that  tuberculosis  is  necessarily  an  evil.  We  fix  our 
eyes  upon  the  advanced  case  of  tuberculous  disease,  a  piti- 
able sight  indeed,  and  that  for  us  spells  tuberculosis,  but 
we  forget  that  such  a  case  is  the  comparative  exception,  the 
illustration  of  a  failure  in  immunization ;  we  forget  that  the 
majority  of  the  population  never  know  that  they  are  tuber- 
culized!  It  is  as  if  we  confounded  vaccination  with  small- 
pox and  because  the  latter  is  a  terrible  disease  we  concluded 
that  vaccination  against  it  is  also  terrible !     The  simile  is 


SOME  PRACTICAL  CONSIDERATIONS  183 

of  course,  not  perfect,  for  the  laws  of  immunity  against 
smallpox  are  not  the  same  as  the  laws  against  tuberculosis. 
There  is,  therefore,  all  the  more  need  that  we  shall  set  our- 
selves resolutely  to  work  to  establish  beyond  all  contro- 
versy what  the  laws  of  tuberculous  immunization  really  are. 
Becoming  convinced  that  we  must  live  with  the  tubercle 
bacillus,  the  next  step  is  to  learn  how  to  get  along  with  it 
on  the  best  possible  terms.  There  seems  to  be  no  reason 
why  we  should  not  aspire  to  the  elimination  of  all  manifest 
tuberculous  disease  —  it  simply  means  increasing  the  per- 
centage, already  so  large,  of  the  successfully  vaccinated. 
The  watchword  should  be :  vaccination  against  tuberculosis 
for  all  —  no  manifest  tuberculosis  for  anybody ! 

That  all  shall  receive  adequate  vaccination  without  their 
knowledge  or  desire  demands  that  the  community  shall  be 
absolutely  steeped  in  infection.  Where  all  shall  receive 
enough  in  the  present  haphazard  method,  many  must  re- 
ceive too  much.  The  Jewish  race,  longest  devoted  to  the 
life  of  cities,  shows  the  best  vaccination.  But  even  they 
pay  dearly  for  their  immunity  by  a  considerable  percentage 
of  losses. 

We  have  done  our  best  during  the  last  quarter  century  to 
diminish  tuberculous  infection,  and  something  has  been  ac- 
complished, no  doubt,  in  lessening  the  size  and  frequency 
of  infecting  doses.  Fortunately  as  yet  we  have  not  suc- 
ceeded in  diminishing  by  one  iota  the  morbidity  of  the  dis- 
ease. Not  that  such  diminution,  and  that  to  the  point  of 
extinction  is  not  desirable,  but  we  are  not  yet  ready  for  it. 
For  as  soon  as  we  diminish  the  morbidity  the  danger  arises 
that  the  opportunities  for  tuberculization  will  likewise 
diminish,  that  after  a  deceptive  lull  cases  of  acutely  fatal 
tuberculosis  will  begin  to  take  the  place  of  the  former  more 
benign  types  of  the  disease.     We  must  provide  against  this 


184  EPIDEMIOLOGY  OF  TUBERCULOSIS 

danger  in  our  future  program.  This  can  only  be  done  by 
substituting  an  artificial  premeditated  infection  for  the 
present  infection  by  chance.  G.  B.  Webb  has  already  made 
a  courageous  beginning  in  this  direction,  but  before  the 
medical  profession  can  be  prepared  to  enter  into  the  field 
on  a  large  scale  the  study  of  one  generation  will  be  required 
in  order  to  ascertain  the  necessary  facts.  We  need  to  study 
the  later  history  of  those  who  were  positive  to  the  von  Pir- 
quet  reaction  as  compared  with  that  of  the  negative  cases 
in  each  of  the  years  of  childhood  in  order  to  ascertain  the 
year  of  life  most  favorable  for  infection,  for  we  do  not 
know  from  large  series  of  cases  what  the  relative  proba- 
bility as  to  the  future  development  of  manifest  tuberculosis 
is  of  the  negative  and  of  the  positive  cases  in  the  von  Pir- 
quet  reaction  in  the  different  age  groups.  This  involves 
the  systematic  use  of  the  cutaneous  tuberculin  reaction  on 
the  children  of  all  ages  after  infancy.  The  children  who 
react  positively  would  require  no  farther  tests,  those  who 
give  a  negative  reaction  should  be  tested  again  each  suc- 
ceeding year  (or  more  often  if  practicable)  until  a  positive 
reaction  is  obtained.  A  careful  record  should  be  kept  by 
name  of  all  the  children  that  have  been  tested  and  the 
history,  particularly,  of  course,  the  tuberculosis  history,  of 
each  child  should  be  followed  at  least  up  to  the  thirtieth 
year.  It  being  ascertained  that  a  given  child  has  recently 
become  infected,  proper  steps  can  be  taken  to  insure  the 
best  possible  care  for  it,  to  the  end  that  the  infection  may 
remain  latent.  There  can  be  no  doubt  that  the  first  half 
year  after  infection  is  a  critical  time  for  the  child.  Proper 
attention  at  this  time  would  do  more  to  lower  the  morbidity 
and  mortality  from  tuberculosis  than  anything  except  pre- 
venting the  infant  from  coming  into  contact  with  the  con- 
sumptive.    The  work  would  be  of  great  value  if  limited  to 


SOME  PRACTICAL  CONSIDERATIONS  185 

the  acquisition  of  data  to  be  utilized  only  for  the  prophy- 
lactic care  of  recently  infected  children.  We  should,  how- 
ever, aspire  to  more.  What  an  enormous  mass  of  valuable 
data  is  lost  because  acquired  a  little  at  a  time  by  many 
individuals  and  never  collated!  Furthermore,  many  even 
of  the  facts  that  are  of  record  lose  much  of  their  value  be- 
cause imperfectly  recorded  or  because  individual  investiga- 
tors introduce  variations  in  their  methods  so  that  their 
results  are  not  comparable  with  one  another.  It  is  also  to 
be  remembered  that  the  observations  to  be  of  the  greatest 
value  must  be  continued  for  many  years,  probably  beyond 
the  lifetime  of  some  who  had  been  active  at  the  inception 
of  the  work.  For  all  these  reasons  it  is  necessary  that  the 
work  shall  be  carried  on  by  an  organization.  In  view  of 
the  multitude  of  willing  workers  in  the  field  of  tuberculosis 
to  whom  could  we  better  commit  this  task  than  to  the  local 
tuberculosis  organizations,  the  Anti-tuberculosis  Associa- 
tions ?  Every  local  anti-tuberculosis  association  would  then 
become  a  record  office  of  the  tuberculization  of  the  com- 
munity. The  extreme  value  of  such  a  series  of  facts  quite 
aside  from  the  question  of  artificial  tuberculosis  infection  is 
plainly  evident.  The  facts  will  be  at  hand  after  thirty 
years  for  that  purpose  if  they  are  wanted,  and  in  the  mean- 
time the  guidance  that  they  have  furnished  for  prophylaxis 
and  for  treatment  and  the  additions  that  they  will  make  to 
our  statistical  information  will  have  richly  repaid  the 
trouble  of  their  collection.  Small  series  of  observations  are 
worth  very  little.  What  is  needed  is  ah  enormous  number 
of  entirely  objective  and  easily  ascertained  facts  which, 
with  a  little  instruction,  can  be  collected  by  any  intelligent 
layman.  The  facts  as  to  tuberculin  sensitiveness  are  of 
course  of  prime  importance,  but  data  as  to  mode  of  infec- 
tion would  not  be  out  of  place  —  facts  as  to  the  entrance  of 


186  EPIDEMIOLOGY  OF  TUBERCULOSIS 

a  consumptive  into  a  family  of  young  children,  for  example, 
should  be  recorded  with  especial  care.  It  is  highly  im- 
portant, however,  that  the  records  shall  be  confined  to  ob- 
jective facts  and  that  the  observers  shall  not  be  too  ready 
to  identify,  more  or  less  by  conjecture,  the  source  of  infec- 
tion in  the  individual  cases  —  it  is  unscientific  and  mis- 
leading to  create  classifications  for  hereditary  infection,  for 
infection  by  chance  or  ephemeral  contact  and  the  like.  And 
it  seems  important  to  the  writer  that  positive  reactions 
shall  be  interpreted  (in  the  absence  of  manifest  tuberculous 
disease)  in  terms  of  vaccination  and  not  in  terms  of  tuber- 
culosis. The  child  that  has  recently  become  positive  to  the 
skin  test  is  usually  not  ill,  but  simply  requires  watching. 
To  create  a  tuberculosis  "  scare  "  by  labeling  such  cases 
"  tuberculosis  "  would  do  much  harm.  Too  great  care  can 
not  be  taken  to  guard  against  such  an  evil.  In  order  that 
the  statistics  shall  be  homogeneous,  tuberculin  of  the  same 
strength  (undiluted)  should  be  used  and  the  methods  of 
scarification  and  of  interpreting  the  results  should  be 
standardized  as  well  as  the  methods  of  keeping  the  records, 
hence  the  control  and  oversight  of  the  work  should  be  in  the 
hands  of  the  National  Tuberculosis  Association. 

An  excellent  beginning  has  been  made  at  Framingham, 
Mass.,  where  tuberculin  is  employed  as  one  of  the  means  of 
diagnosis.  Much  that  is  done  there  cannot  be  imitated 
elsewhere  for  lack  of  funds,  but  there  seems  to  be  no  good 
reason  why  the  benefits  of  the  cheap  and  easy  tuberculin 
skin  test  should  not  be  extended  to  many  communities 
where  a  general  medical  survey  would  be  impracticable. 

Some  classes  of  our  population  change  their  residences 
so  frequently  that  it  will  prove  difficult  to  keep  many  of  the 
children  under  oversight.  For  that,  as  well  as  for  many 
other  reasons,  the  numbers  examined  should  be  large.     To 


SOME  PRACTICAL  CONSIDERATIONS  187 

propose  to  examine  ten  thousand  children  may  seem  a  too 
ambitious  program,  but  could  not  twenty  anti-tuberculosis 
associations  easily  examine  and  follow  up  500  cases  apiece? 
The  writer  is  sanguine  enough  to  hope  for  statistics  from 
an  even  larger  number  of  children. 


Laboratory  Problems 

It  has  long  been  a  source  of  surprise  to  the  writer  that  so 
little  interest  has  been  taken  in  the  question :  What  is  the 
meaning  of  the  negative  percentage  in  tuberculin  tests? 
Will  all  civilized  adults  react  to  tuberculin,  if  given  in  a 
sufficient  dose,  or  is  there  a  certain  percentage  which  is 
really  not  infected  at  all  with  tuberculosis?  Those  who 
have  followed  the  discussion  of  this  subject  will  agree  that 
the  negative  percentage  must  be  a  small  one,  at  least  in  the 
large  centres  of  population.  Still  it  is  of  importance  that 
the  question  shall  be  definitely  settled.  A  tuberculin  skin 
test  in  many  remote  farming  communities  in  which  tuber- 
culosis seems  to  be  rare  would  throw  light  upon  the  im- 
portant question  whether  the  absence  or  relative  rarity  of 
manifest  tuberculosis  disease  means  infrequent  opportuni- 
ties for  infection  or  a  high  resistance. 

As  has  already,  however,  been  pointed  out,  the  skin  test 
must  not  be  too  implicitly  relied  upon  as  giving  the  true 
percentage  of  tuberculization  of  a  group  of  individuals  — 
it  shows  the  greater  part,  not  all  of  the  tuberculous  infec- 
tion present.  For  the  accurate  determination  of  the  tuber- 
culosis situation  in  a  given  group  or  community  we  much 
need  to  supplement  the  findings  of  the  tuberculin  tests  by 
some  other  procedure. 

The  complement-binding  reaction  at  once  suggests  itself. 
But  except  that  no  objections  can  be  raised  as  to  its  safety, 


188  EPIDEMIOLOGY  OF  TUBERCULOSIS 

the  complement-binding  reaction  in  tuberculosis  has  the 
same  shortcomings  as  the  tuberculin  tests,  that  is,  it  is  a 
coarse  test  and  does  not  reveal  all  of  the  tuberculosis  pres- 
ent. Laboratory  workers  have  exercised  their  ingenuity 
to  produce  tuberculosis-antigens  which  shall  not  be  too  sen- 
sitive but  which,  producing  positive  results  only  in  active 
tuberculous  disease,  shall  render  possible  the  elimination 
from  farther  consideration  of  those  in  whom  there  has 
simply  been  "  a  previous  contact  with  tuberculosis  ".  But 
from  the  standpoint  of  those  who  would  settle  what  the 
writer  regards  as  the  most  important  epidemiological  ques- 
tion before  the  medical  world  —  the  exact  amount  of  tuber- 
culization of  the  civilized  community  —  the  antigens  are 
less  rather  than  more  sensitive  than  they  should  be. 
According  to  Fishberg1  the  complement-binding  reaction 
appears  to  be  of  about  the  same  value  in  diagnosis  as  the 
von  Pirquet  skin  reaction.  Ninety-five  per  cent,  of  posi- 
tive results  have  been  reported  in  tuberculous  cases  and 
Craig2  found  65  per  cent,  of  clinically  inactive  cases  of  pul- 
monary tuberculosis  to  give  positive  reactions  (these  cases, 
however,  being  for  the  most  part  patients  in  a  tuberculous 
sanatorium) .  Evidently  if  we  expect  the  complement- 
binding  reaction  to  detect  all  of  the  cases  which  have  been 
in  contact  with  tuberculosis,  we  should  have  at  least  95  per 
cent,  of  positive  results  in  healthy  adults,  for  that  percent- 
age has  been  exceeded  by  the  cutaneous  test  in  some  series 
and  Opie3  found  one  hundred  per  cent,  of  tuberculosis  in 
autopsies  of  all  persons  eighteen  years  or  over  by  his  radio- 
graphic methods.  Alstaedt4  has  stated  that  of  the  popula- 
tion of  Hamburg  which  makes  use  of  the  public  hospitals 

1  Pulmonary  Tuberculosis,  2d  Edition.     1919,  p.  349. 

*Am.  Jour.  Med.  Sci.     1915,  p.  781. 

"Jour.  Exp.  Med.     Vol.  25,  1917,  p.  855. 

4Beitr.  z.  Klinik  d.  Tub.     Fourth  Supplementary  Vol.,  p.  246. 


SOME  PRACTICAL  CONSIDERATIONS  189 

hardly  a  child  reaches  the  threshold  of  its  second  year  with- 
out giving  a  positive  reaction  to  Deycke  and  Much's  "  par- 
tial antigens ".  This  amazing  statement  should  be  con- 
firmed by  extended  investigation  before  we  can  accept  it  as 
proof  of  so  extensive  and  early  tuberculization  of  young 
children.  If  true  it  shows  that  the  complement-binding 
reaction  may  be  made  of  extreme  delicacy  so  that  it  may 
become  an  instrument  for  the  detection  of  tuberculous  sen- 
sitization superior  to  tuberculin,  and  may  reveal  a  stage  of 
earliest  tuberculous  infection  to  which  biological  tests  have 
hitherto  been  blind.  The  subject  would  seem  to  urgently 
demand  further  investigation. 


The  individual  laboratory  worker  who  studies  tuberculo- 
sis experimentally  labors  under  the  necessity  of  employing 
a  dosage  of  tubercle  bacilli  which  is  excessive  in  comparison 
with  the  probable  dosage  of  natural  infection,  because  he 
feels  that  he  must  produce  infection  within  a  reasonable 
time  and  in  such  a  way  as  to  preclude  the  probability  of 
confusion  with  intercurrent  natural  infections.  Hence  we 
know  only  too  well  what  happens  when  infections  have  been 
produced  by  too  large  doses  of  tubercle  bacilli,  but  very 
little  as  to  the  manner  in  which  an  animal  should  be  in- 
fected in  order  to  lead  to  the  highest  possible  immuniza- 
tion. We  know  from  the  experiments  of  Romer  that 
guinea  pigs  infected  with  minutest  doses  of  attenuated 
tubercle  bacilli  require  months  in  which  to  develop  a  reac- 
tivity to  tuberculin,  and  Hamburger  has  shown  that  the 
length  of  the  period  of  incubation  varies  in  general  with 
the  size  of  the  infecting  dose.  The  dosage  is  therefore  a 
matter  of  the  highest  importance  if  animal  inoculation  is 
to  guide  us  in  the  study  of  the  practicability  of  human  in- 
oculation.    The  minimal  infecting  dose  of  tubercle  bacilli 


190  EPIDEMIOLOGY  OF  TUBERCULOSIS 

has  been  ascertained  and  reported  by  several  observers. 
Their  results  do  not  agree  with  one  another  and  are  of  no 
value  for  one  who  would  study  small  natural  infections.  For 
what  they  mean  by  minimal  dosage  is  the  dose  that  will 
produce  an  undoubted  infection  in  so  short  a  time  as  to 
avoid  the  criticism  that  such  infection  as  may  become  ap- 
parent might  not  have  been  the  result  of  the  procedures 
adopted  by  the  investigator. 

Contact  with  the  pneumococcus,  the  meningococcus  and 
the  diphtheria  bacillus  appears  to  effect  a  certain  immuni- 
zation, although  there  has  never  been  an  actual  infection  in 
the  ordinary  sense  of  the  word.  This  is  shown  by  the  fact 
that  carriers  of  these  microorganisms,  while  by  no  means 
absolutely  immune  to  attacks  of  the  enemy  which  they  har- 
bor, are  nevertheless  distinctly  less  susceptible  than  those 
who  have  never  had  the  opportunity  to  accommodate  them- 
selves to  its  presence. 

May  we  not  account  for  the  superiority  of  the  immuniza- 
tion of  the  civilized  individual  against  tuberculosis  in  an 
analogous  way?  Evidently  immunization  in  general  is 
best  effected  when  the  earliest  contact  is  occult.  In  other 
words,  it  is  desirable  to  habituate  the  body-cells  to  the  pres- 
ence of  a  new  poison  in  the  most  gradual  manner.  Hence 
for  the  best  results  actual  inflammatory  reaction  should  be 
deferred  as  long  as  possible  after  the  reception  of  the  virus. 

Here  is  an  almost  untrodden  field  for  investigation.  What 
we  need  to  know  in  tuberculosis  is  the  result,  after  months 
and  years,  as  to  the  acquisition  of  an  immunization,  of  in- 
fections by  the  mouth  and  otherwise  with  minimal  and 
small  doses  of  tubercle  bacilli  in  animals  which  have  been 
most  scrupulously  shielded  against  reinfections.  An  enor- 
mous number  of  animals  would  be  required  in  order  to 
allow  for  losses  by  intercurrent  disease  and  to  guard  against 


SOME  PRACTICAL  CONSIDERATIONS  191 

the  objection  that  positive  results  are  due  to  chance  reinfec- 
tions. The  time  and  expense  would  be  so  great  that  the 
investigation  could  only  be  undertaken  by  an  institution 
with  ample  means. 

Such  study  is  an  absolute  prerequisite  to  any  attempt  at 
the  artificial  infection  with  tubercle  bacilli  of  the  human 
subject  and  the  knowledge  obtained  by  it  of  the  natural 
history  of  the  small  tuberculous  infection  would  compen- 
sate for  the  labor  involved,  even  though  some  future  inves- 
tigator shall  immortalize  himself  by  the  discovery  of  a 
method  of  immunization  against  tuberculosis  by  means  of 
non-living  antigens. 


The  Care  of  the  Tuberculous  Indian 
One  of  the  most  dangerous  doctrines  relating  to  prophy- 
laxis is  that  good  health  prevents  tuberculous  infection.  It 
is  true,  no  doubt,  that  good  health  will  prevent  tuberculous 
infection  from  becoming  tuberculous  disease,  but  good 
health  has  nothing  to  do  with  the  reception  of  the  tubercle 
bacillus  into  the  body.  We  have  seen  the  evils  which  ensue 
when  the  consumptive  comes  into  contact  with  an  unpro- 
tected race.  An  American  writer  remarked  fifteen  years 
ago :  "  It  seems  that  the  Indian  was  free  from  tuberculosis 
before  his  contact  with  the  whites,  living  as  he  did  in  the 
open  air  and  without  alcohol ".  J.  D.  Hunter,1  after  hav- 
ing been  a  captive  among  the  Indians  nearly  a  century  ago, 
expressed  the  opinion  repeatedly  that  intemperance  was  the 
principal  cause  of  the  prevalence  of  tuberculosis  among 
them.  Alcohol,  however,  can  not  be  even  an  important  acces- 
sory cause  of  tuberculous  disease,  as  Hutchinson  points  out, 

1  Memoirs  of  Captivity  among  the  Indians.  London,  1822.  Also:  N*  Y. 
Med.  and  Phys.  Jour.,  1822,  p.  171.  Cited  by  Hrdlicka,  Bull.  No.  36, 
Bureau  of  Am.  Ethnology. 


192  EPIDEMIOLOGY   OF  TUBERCULOSIS 

because  when  liquor  is  to  be  had  at  all  there  is  never  enough 
so  that  any  can  be  spared  for  women  and  children.  Hence 
the  class  that  suffers  most  among  them,  the  children,  do  not 
consume  it.  The  writer  would  be  the  last  to  object  to  any 
measures  calculated  to  improve  the  health  of  and  to  restrict 
drunkenness  among  the  Indians,  but  the  evil  of  such  teach- 
ings is  that  they  divert  the  attention  from  more  important 
matters,  that  we  shall  be  satisfied  if  regulations  are  adopted 
for  the  exclusion  of  alcohol,  for  example,  and  if  it  appears 
that  alcohol  is  nevertheless  not  excluded,  that  we  shall  feel 
that  at  least  we  have  done  what  we  could  to  help,  whereas 
nothing  whatever  has  been  done  by  us  for  the  really  im- 
portant thing  —  the  determination  of  the  degree  of  tuber- 
culization of  the  Indian  community  and  the  adoption  of 
measures  which  shall  protect  those  who  most  need  protec- 
tion. Hrdlicka1  recommends  that  the  tuberculin  test  (skin 
reaction)  shall  be  applied  to  children  who  are  to  be  sent  to 
the  large  Indian  schools  and  that  all  cases  in  which  the  reac- 
tion points  to  infection  shall  be  denied  admission.  Now 
the  large  schools,  especially  the  so-called  non-reservation 
schools  (one  at  Phoenix,  Arizona,  has  a  capacity  of  1000 
pupils)  are  objectionable  if  the  children  are  not  already 
immunized  by  previous  infection  because  those  who  are 
not  thus  protected  are  very  certain  to  become  infected 
there.  Severe  tuberculosis  in  Indian  schools  has  caused 
much  trouble  in  the  past  and  the  regulation  of  the  school 
life  of  the  Indian  child  seems  one  of  the  measures  that 
promise  most  in  improving  the  conditions  as  to  tuberculo- 
sis. Young  children  who  are  not  likely  to  have  already 
become  infected  should  not  be  sent  away  to  school  at  all. 
Older  children  (10  to  15  years  of  age)  who  are  uninfected 
are  in  the  gravest  danger  at  such  schools  because  it  seems 

1  Loc.  cit. 


SOME  PRACTICAL  CONSIDERATIONS  193 

probable  that  within  limits  the  older  the  individual  is  at 
time  of  infection  the  greater  the  danger  in  such  infec- 
tion. Therefore,  in  the  writer's  judgment,  children 
should  not  be  allowed  to  attend  the  larger  schools 
unless  they  have  a  positive  skin  reaction  to  tuberculin. 
There  is  danger  here  that  those  who  react  positively  may 
be  on  the  point  of  breaking  down  with  manifest  tuberculo- 
sis of  severe  type,  so  that  long  railway  journeys  will  lead  to 
disaster.  We  would  therefore  make  the  further  suggestion 
that  no  Indian  child  be  sent  to  boarding  school  unless  he  is 
in  apparently  good  health,  shows  at  least  no  marked  glandu- 
lar involvement,  gives  no  physical  signs  of  tuberculosis  of 
the  lungs  and  has  been  positive  for  the  von  Pirquet  reaction 
for  at  least  one  year.  In  other  words,  a  tuberculous  vacci- 
nation should  be  required  as  well  as  a  vaccination  against 
smallpox. 

Some  of  the  Indian  tribes  have  been  studied  to  ascertain 
what  percentage  of  families  were  free  of  suspicion  of  tuber- 
culosis. Hrdlicka  reports  that  among  the  Menominee 
Indians  40  per  cent.,  among  the  Sioux  34  per  cent.,  and 
among  the  Mohave  Indians  58.2  per  cent,  of  families  ap- 
peared not  to  have  tuberculous  members.  But  inspection, 
anamnesis  and  even  physical  examination  are  not  enough  to 
determine  such  facts.  The  idea  is  a  good  one  so  far  as  it 
goes  but  the  cutaneous  test  should  be  resorted  to.  If  as 
the  result  of  such  a  test  it  should  appear  that  the  parents  or 
the  older  children  of  a  family  have  a  positive  skin  reaction, 
the  child  in  question  might  be  permitted  to  go  to  the  local 
school,  the  idea  being  that  if  not  already  infected  at  home 
he  soon  will  be.  But  if  the  majority  of  the  family  groups 
are  really  not  infected  at  all,  it  might  be  well  to  exclude  all 
that  react  positively  and  confine  the  school  privileges  to  the 


194  EPIDEMIOLOGY  OF  TUBERCULOSIS 

uninfected,  or  possibly  provide  separate  schools  for  the  two 
groups. 

However  desirable  it  may  be  that  children  should  be  in- 
fected with  tuberculosis  at  a  comparatively  early  age,  in  the 
present  state  of  phthisiology  one  would  not  perhaps  be  jus- 
tified in  deliberately  exposing  an  unprotected  individual  to 
the  dangers  of  chance  infection,  yet  at  the  same  time  it 
should  be  emphasized  that  the  dangers  of  primary  infection 
in  the  active  years  of  later  childhood  are  so  great  that  the 
negatively  reacting  individual  should  be  regarded  as  one 
who  especially  requires  protection. 


Tuberculosis  in  German  Southwest  Africa 
The  natives  of  German  Southwest  Africa  having  revolted 
against  the  Germans,  lost  heavily  in  the  ensuing  warfare. 
Von  Trotha,  according  to  the  British  Blue  Book,1  issued  his 
order  of  extermination  of  the  Hereros  in  August,  1904. 
Many  defenseless  women  and  children,  as  well  as  warriors, 
were  killed  as  the  result  of  this  order  and  the  tribe,  though 
not  exterminated,  was  reduced  from  some  80,000  to  90,000 
souls  to  about  15,000  at  the  end  of  1905,  when  von  Trotha 
relinquished  his  task.  Altogether  about  two-thirds  of  the 
native  population  had  perished  when  peace  was  made. 
Besides  losses  in  combat,  according  to  Kiilz,  there  were 
losses  incident  to  the  assembling  of  workers  for  tribute. 
The  prisoners  of  war  who  were  sent  away  perished  for  the 
most  part.  After  pacification  a  station  was  built  and  the 
people  were  required  to  work,  at  first  in  payment  of  tribute, 
at  a  later  time  in  payment  of  taxes.  They  were  in  part 
compelled  to  change  their  places  of  residence  in  order  to  be 
under  closer  supervision.     New  lands  had  to  be  cleared  of 

'Report  on  the  Natives   of   Southwest  Africa  and  their  Treatment  by 
Germany.     British  Blue  Book,  August,  1918. 


SOME  PRACTICAL  CONSIDERATIONS  195 

tropical  growth  with  primitive  instruments,  for  the  people 
were  not  only  obliged  to  raise  their  own  food  but  also  to 
provide  for  the  multitude  of  strangers  who  now  penetrated 
the  country.  The  land  that  formerly  knew  little  of  traffic, 
says  Kiilz,1  was  now  traversed,  not  by  hundreds,  but  by 
thousands  of  bearers  and  traders,  who  brought  wares  in 
exchange  for  rubber.  All  of  these  thousands  had  to  be  fed 
from  the  fields  though  the  natives  starved;  and  indeed 
famine  made  its  appearance  among  them  in  some  places. 
This  led  the  way  for  smallpox  and  dysentery,  which  pre- 
vailed most  in  the  parts  most  traveled,  so  that  the  sorely 
tried  and  discouraged  remnant  saw  their  numbers  still  far- 
ther reduced  by  acute  infectious  diseases,  as  well  as  by  those 
other  gifts  of  civilization,  syphilis  and  alcohol.  As  for 
tuberculosis,  Kiilz  says  that  it  is  undoubtedly  present 
though  not  yet  widespread.  Under  the  circumstances  it 
will  surely  prevail,  as  it  has  elsewhere,  and  in  time  its 
ravages  may  surpass  those  of  the  more  acute  infections. 
Its  dangers  have  been  ignored  in  the  past  until  it  was  too 
late.  Civilized  nations,  not  excepting  our  own,  have  a 
heavy  burden  of  responsibility  for  ignorant,  if  not  cruel, 
neglect  of  helpless  peoples  who  have  come  under  their 
dominion.  It  has  been  ignorance  rather  than  cruelty  in  the 
past,  so  far  as  tuberculosis  is  concerned,  but  the  excuse  of 
ignorance  ought  no  longer  to  be  accepted. 

The  desideratum,  of  course,  is  the  prevention  of  massive 
infections,  a  most  difficult  problem  under  the  conditions. 
At  least  a  benevolent  government  can  diminish  the  burdens 
formerly  placed  upon  the  afflicted  race  until  such  time  as 
the  people  have  been  able  to  recuperate.  In  many  cases, 
no  doubt,  the  question  whether  infection  with  tuberculosis 
shall  result  in  immunization  or  death  depends  upon  the  way 

1Ardhiv.  fur  Rassen-u.  Geselltechafts-Biologie.     Vol.  7,   1910,  p.  533. 


196  EPIDEMIOLOGY   OF  TUBERCULOSIS 

in  which  the  individuals  are  treated.  Exploitation  of  the 
natives  in  Africa  and  elsewhere  is  responsible  for  much  of 
the  frightful  mortality  which  has  reduced  to  a  handful  so 
many  once  powerful  tribes.1  The  policy  of  the  Germans  in 
Southwest  Africa,  in  peace  as  well  as  in  war,  as  some  of 
their  own  writers  admit,  was  calculated  to  cause  the 
gradual  disappearance  of  that  population  upon  which  the 
future  of  the  colony  depends.  There  is  every  inducement 
from  an  economic  as  well  as  from  a  benevolent  point  of 
view  to  take  up  the  prophylaxis  of  tuberculosis  as  seriously 
as  that  of  other  preventable  diseases. 


Problems  in  Comparative  Epidemiology 
When  Naegeli  was  making  his  classical  investigations  as 
to  the  percentages  of  tuberculosis  to  be  found  at  autopsy, 
he  was  led  to  the  conclusion  that  localized  fibrous  tracts 
leading  from  the  hilus  to  the  surface  of  the  apex  practically 
always  indicated  an  old  tuberculosis  even  though  micro- 
scopic study  did  not  discover  any  histological  changes  that 
were  absolutely  characteristic.2  And,  he  says,  he  reached 
that  conclusion  because  he  found  an  unbroken  series  of 
transition  pictures  which  progressed  from  typical  tubercu- 
losis to  those  findings  which  in  themselves  prove  nothing. 
With  this  interpretation  Naegeli  found  97  to  98  per  cent, 
of  positive  cases.     Burckhardt,8  who  made  a  similar  inves- 

1 "  It  is  claimed  that  the  (labor)  traffic  will  depopulate  the  sources  of 
supply  within  the  next  twenty  or  thirty  years.  Queensland  is  a  very 
healthy  place  for  white  people  —  death-rate  12  in  1,000  of  the  population  — 
but  the  Kanaka's  death-rate  is  away  above  that.  The  vital  statistics  for 
1893  place  it  at  52;  for  1894  <  Mack'ay  district),  68.  The  first  six  months 
of  the  Kanaka's  exile  are  peculiarly  perilous  for  him  because  of  the  rigors 
of  the  new  climate.  The  death-rate  among  the  new  men  has  reached  as 
high  as  180  in  the  1,000.  In  Die  Kanaka's  native  home  his  death-rate  is 
12  in  time  of  peace  and  15  in  time  of  war.  Thus  exile  to  Queensland  is 
twelve  times  as  deadly  for  him  as  war".  Mark  Twain,  Following  the 
Eouator,  1897,  p.  88. 

-  Virohow's  Archiv.     Vol.   160.  p.  426. 

'Zeitschr.  f.  Hvg.  u.  Infekt.  Krankhtn.  Vol.  53,  1906.  p.  130. 


SOME  PRACTICAL  CONSIDERATIONS  197 

tigation  and  counted  only  those  cases  tuberculous  which 
showed  either  calcifications  or  caseations,  obtained  91  per 
cent,  of  positive  cases  In  his  autopsies,  yet  he  admits  that 
Naegeli's  percentages  very  probably  represented  more 
nearly  the  true  facts.  Whether  we  are  willing  to  make  the 
same  admission  or  not,  it  is  believed  to  be  true  that  such 
localized  fibroses  in  the  large  majority  of  cases  indicate 
tuberculosis.  It  is  one  of  the  most  interesting  facts  in  the 
radiography  of  the  lung  that  by  it  similar  fibroses  are  found 
to  be  almost  universal.  Just  as  Naegeli  found  an  unbroken 
series  of  fibroses  proceeding  from  the  non-pathognomonic 
to  the  pathognomonic,  so  the  X-ray  shows  in  apparently 
healthy  persons  an  unbroken  series  of  localized  opacities 
extending  upwards  from  the  hilus  as  thickened  lines,  some 
of  which  reach  the  surface  of  the  apex,  while  others  appear 
to  terminate  in  the  deep  lung.  Of  the  latter  group,  some 
show  dots  at  the  bifurcation  of  the  bronchi,  which  un- 
doubtedly indicate  tubercle,  others  similar  in  other  respects 
do  not.  Of  those  that  frankly  reach  the  pleura,  some 
terminate  in  what  are  evidently  tuberculous  foci,  while  in 
others,  perhaps,  only  a  superficial  branching  of  the  thick- 
ened lines  is  to  be  made  out  in  the  apex.  Recent  experience 
has,  moreover,  convinced  the  writer  that  the  opacities  in 
question  more  frequently  reach  the  apex  than  may  appear, 
the  thickened  lines  in  apparently  healthy  persons  being 
often  so  delicate  as  to  be  revealed  only  by  an  unusually 
happy  exposure  and  development.  We  are  justified  in  the 
view  that  the  X-ray  findings  in  general  confirm  the  presence 
of  that  practically  universal  tuberculization  of  civilized 
adults  which  has  been  so  abundantly  proved  to  exist  by 
tuberculin  tests  and  autopsy  findings.  Now,  the  impor- 
tance of  that  surprising  fact  in  the  present  connection  is 
this :  it  shows  that  successful  vaccination  against  tubercu- 


198  EPIDEMIOLOGY   OF  TUBERCULOSIS 

losis  in  the  large  majority  of  our  race  is  obtained,  not  as  an 
invisible  sensitization  and  immunization  of  the  body-cells 
solely,  nor  solely  as  a  lymphoid  hyperplasia  in  lymphatic 
glands,  but  at  the  cost  and  at  the  risk  of  a  deep  lymphan- 
gitis, which  heads  toward  the  place  of  danger,  the  superfi- 
cial lung.  The  difference  between  the  lymphangitis  with 
and  the  lymphangitis  without  extension  to  the  apex,  and 
also  the  difference  between  an  apical  process  that  hea!ls, 
often  without  the  subject  having  been  aware  of  its  ex- 
istence, and  one  that  extends  as  an  active  superficial  lesion 
of  the  parenchyma  seems  fundamentally  very  slight  from 
the  anatomical  point  of  view. 

What  is  it  that  enables  the  tubercle  bacillus  to  progress 
in  the  less  well  localized  lesions?  First  of  all,  of  course, 
the  resistance,  the  degree  of  immunization  of  the  subject, 
but  the  amount  of  blood  present  is  also  an  important  factor. 
Other  things  being  equal,  that  case  will  be  in  the  greatest 
danger  of  a  progression  of  the  disease  in  which  the  conges- 
tion of  the  lungs  is  most  marked.  True,  the  congestion  of 
the  focus  is  related  to  the  intensity  of  the  inflammation,  so 
that  we  come  back  again  to  the  resistance  of  the  individual, 
nevertheless  improvement  is  effected  by  diminution  of  the 
congestion  of  the  lung  through  measures  which  do  not 
directly  depend  upon  the  degree  of  immunization.  We 
know  that  artificial  pneumothorax  will  often  arrest  an  other- 
wise progressive  tuberculosis.  Here  collapse  of  the  lung 
effects  rest  of  the  diseased  parts  and  also  ultimately  a  rela- 
tive dryness  of  the  pulmonary  tissues  with  a  diminution  of 
the  amount  of  the  circulating  lymph,  the  benefit  of  rest  of 
the  lung  being  usually  explained  as  due  to  the  fact  that 
poisoned  lymph  is  no  longer  so  freely  spread  through  the 
healthy  parts  by  the  movements  of  respiration. 


SOME  PRACTICAL  CONSIDERATIONS  199 

We  are  therefore  justified  in  asking  the  question:  is  it 
possible  that  the  scale  may  sometimes  be  turned  against  the 
patient  by  a  congestion  of  the  lung,  from  causes  more  or 
less  independent  of  the  intensity  of  the  focal  inflammation  ? 
A  question  of  this  nature  could  not  be  answered  in  the  indi- 
vidual case  in  such  a  way  as  to  compel  acceptance,  but  light 
could,  it  would  seem,  be  thrown  upon  it  by  epidemiological 
study  in  which  nations  or  large  groups  of  individuals  of 
different  nations  are  compared  with  one  another. 

Is  it  true  that  the  Chinese,  though  thoroughly  tubercu- 
lized  and  though  defying  most  of  the  laws  of  hygiene  as  we 
understand  them,  have  as  low  or  lower  rates  of  tuberculosis 
mortality  than  we  do;  that  they  have  less  pulmonary  con- 
gestion, less  pneumonia  than  we  do  ?  If  this  is  true,  is  the 
explanation  that  which  they  would  give,  namely,  that  it 
depends  upon  diet?  Or  is  low  mortality  from  tuberculosis 
due  to  a  more  perfect  tuberculization  of  the  Chinese?  The 
Chinese,  while  not  vegetarians  from  choice,  are  largely  so 
from  necessity.  We  have  been  told  by  Kitisato  that  the 
prevalence  of  tuberculosis  is  about  the  same  in  Japan  as  in 
European  countries.  How  do  selected  communities  in 
Japan  and  China  compare  with  one  another  as  to  types, 
incidence  and  mortality  of  tuberculosis,  as  to  the  degree  of 
tuberculization  (positive  percentages  in  the  tuberculin 
skin  test)  and  as  to  the  amount  of  animal  food  consumed? 
How  do  the  Japanese  compare  with  the  Chinese  as  to  the 
prevalence  and  mortality  of  pneumonia?  It  is  of  enormous 
importance  to  epidemiology  to  determine  whether  in  case 
there  is  really  a  lesser  prevalence  of  tubrculosis  and  pneu- 
monia in  China  the  explanation  is  that  nearly  every  one  is 
a  carrier,  or  whether,  on  the  other  hand,  the  tubercle  bacil- 
lus and  the  pneumococcus  are  relatively  rare. 

The  hygiene  of  the  population  of  Bombay,  as  we  have 
seen,  is  described  as  bad.     But  the  death  rates,  already 


200  EPIDEMIOLOGY   OF  TUBERCULOSIS 

quoted,  are  not  high,  certainly  not  as  high  as  would  be  ex- 
pected in  one  of  our  cities,  if  seventy-five  per  cent,  of  the 
inhabitants  lived  in  a  single  dark,  ill-ventilated  room  in 
almost  tropical  heat.  What  is  the  tuberculization  of  the 
population,  what  the  prevalence  of  pneumonia  and  pulmo- 
nary congestions,  if  less  than  with  us,  what  the  nature  of 
their  diet? 

Such  suggestions  are  simply  examples  of  some  of  the  pos- 
sibilities in  what  might  be  called  Comparative  Epidemi- 
ology. Similar  inquiries  might  be  profitable  and  might  be 
more  easily  made  in  many  other  fields.  Concerted  effort 
could  easily  accumulate  such  a  body  of  facts  as  to  settle 
beyond  all  peradventure  some  of  the  basal  questions  in 
tuberculosis  on  which  there  is  as  yet  no  agreement.  It  is 
thought  particularly  desirable  to  learn  the  real  facts  as  to 
tuberculosis  in  China  and  India,  countries  of  ancient  civili- 
zation in  which  tuberculosis  has  prevailed  from  time  imme- 
morial, but,  as  already  remarked,  much  that  is  important 
could  also  (and  more  easily  for  Americans)  be  learned  from 
study  of  the  tuberculosis  of  islands  such  as  Samoa  and 
Porto  Rico,  the  date  of  the  introduction  of  the  disease  being 
comparatively  recent  in  the  former  and  probably  of  con- 
siderable antiquity  in  the  latter. 

No  doubt  superstitions  and  racial  prejudices  will  often 
interfere  with  the  collection  of  the  desired  facts,  but,  it  is 
thought,  the  von  Pirquet  test  could  well  be  given  in  connec- 
tion with  vaccination  for  smallpox  (this  has  been  done  in 
some  places),  and  facts  as  to  the  types,  morbidity  and  mor- 
tality of  tuberculosis  could  be  obtained  when  a  census  is 
taken.1 

1  The  Bureau   of  Health    of  Manila  publishes   in   its   annual  report  the 
mortality  statistics  for  all  important  diseases  by  ages  and  nationalities. 


SOME  PRACTICAL  CONSIDERATIONS  201 

Too  long  we  have  been  content  to  base  our  views  as  to  the 
pathology  and  therapeusis  of  tuberculosis  upon  observa- 
tions in  a  restricted  field.  The  study  of  the  tuberculosis  of 
uncivilized  peoples  is  of  great  value  in  demonstrating  what 
the  course  of  truly  primary  tuberculosis  of  the  adult  is  and 
thereby  furnishing  the  only  satisfactory  explanation  for  the 
apparent  immunity  from  tuberculosis  of  the  majority  of  the 
members  of  civiliztd  communities. 

But  the  writer  is  not  at  all  convinced  that  equally  im- 
portant data  might  not  be  obtained  from  a  tuberculosis  sur- 
vey of  the  teeming  cities  of  the  oldest  civilizations. 

And  to  any  one  who  should  be  prompted  to  enter  upon 
such  investigations,  we  would  commend  the  saying  of  Lieb- 
man:1  "One  can  not  search  after  truth  and  yet  at  the 
same  time  attempt  to  decide  in  advance  whither  the  way 
should  lead  ". 

1  Quoted  by  Deycke,  Med.  Krit.  Blatter.     Vol.  1,  Heft   1,  p.  72. 


CHAPTER  XIII 
SUMMARY  AND  CONCLUSIONS 

In  the  days  when  consumption  was  not  regarded  as  an 
infectious  disease  it  was  believed  to  be  due  to  climatic  con- 
ditions which,  however,  affected  only  the  individuals  who 
had  the  appropriate  diathesis.  Attempts  to  explain  the 
incidence  of  the  disease  under  widely  varying  conditions  of 
climate  led  to  all  manner  of  contradictions,  which  became 
more  marked  when  the  study  of  tuberculosis  was  carried  to 
remote  parts  of  the  globe  and  it  was  discovered  that  the 
disease  raged  more  severely  in  the  most  salubrious  islands  of 
the  Pacific  than  in  the  bleakest  regions  of  the  old  world. 

In  studying  the  dissemination  of  tuberculosis  throughout 
the  world,  it  appears  that,  as  respects  the  types  of  tubercu- 
losis, the  various  countries  are  divided  into  two  classes. 
In  the  one,  tuberculosis  is  widespread,  as  with  us;  in  the 
other  it  is  relatively  rare,  but  the  cases  that  do  occur  are 
rapidly  fatal,  although  under  conditions  favorable  for  it  the 
disease  may  prevail  as  an  epidemic  and  exterminate  entire 
families  and  even  tribes.  This  observation  is  formulated 
in  the  law  of  Romer,  which  is:  Where  tuberculosis  is  a 
rare  disease  the  cases  that  occur  will  be  acute  and  fatal. 
Where  the  disease  is  common  the  type  will  be  chronic  and 
relatively  benign.  In  other  words,  contact  with  tuberculo- 
sis affords  a  certain  protection  against  it. 

In  the  civilized  community  the  apparent  immunity  of  the 
majority  of  the  population  was  accounted  for  by  the  suppo- 
sition that  a  certain  predisposition  was  necessary  for  the 
establishment  of  the  disease,  that  healthy  persons  had  a 

202 


SUMMARY  AND  CONCLUSIONS  203 

degree  of  natural  immunity  against  it  and  that  adults,  by 
reason  of  their  maturity,  had  a  higher  resistance  than 
young  children.  But  when  the  facts  of  the  incidence  of 
tuberculosis  in  certain  remote  parts  of  the  world  became 
known,  it  appeared  that  there  the  disease  operated  in  a  dif- 
ferent manner,  that  it  spared  no  age  of  life  and  no  condition 
of  health,  comporting  itself  in  short  like  other  infectious 
diseases.  The  natural  explanation  for  this  difference  was 
that  it  was  a  question  of  race,  the  race  under  consideration 
having  a  greater  proclivity  to  tuberculosis  than  the  older 
races,  in  which  the  disease  is  apparently  less  easily  ac- 
quired, and  this  is  still  the  usual  explanation  of  the  phe- 
nomenon. It  is  found,  however,  on  closer  observation,  that 
some  individuals  and  communities  show  a  much  higher 
resistance  to  tuberculosis  than  do  other  individuals  and 
communities  of  the  same  race,  also  that  in  certain  regions 
the  type  of  tuberculosis  has  greatly  changed  after  decades 
of  exposure  to  the  disease  from  the  acutely  fatal  to  the 
chronic  and  relatively  benign.  When  in  a  mixed  popula- 
tion certain  nationalities  seem  to  be  more  attacked  by  the 
disease,  than  others,  given  an  equally  long  exposure  to  it,  the 
explanation  is  usually  to  be  found  in  social  and  economic 
rather  than  in  racial  conditions.1 

Now,  if,  under  certain  conditions,  tuberculosis  acts  as  a 
communicable  disease,  its  morbidity  being  in  direct  relation 
to  the  exposure  to  it,  and  if  this  is  not  due  to  differences  of 
race,  it  becomes  difficult  to  account  for  the  apparent  immu- 

1  No  support  is  given  by  experiment  to  the  belief  that  either  an  increased 
predisposition  or  an  increased  resistance  to  tuberculosis  can  be  inherited, 
the  offspring  of  tuberculous  parents  being  neither  more  or  less  prone  to 
tuberculosis  than  other  animals  of  the  same  species  under  similar  condi- 
tions. It  may  be  admitted  that  it  is  quite  probable  that  some  strains  of 
a  certain  race  are  naturally  more  susceptible  to  tuberculosis  than  others 
and  that,  the  less  resistant  individual  dying  out,  there  may  be  in  a  sense 
a  survival  of  the  fittest  among  the  peoples  longest  in  contact  with  the 
tubercle  bacillus.  The  supervention  of  an  immunization,  however,  takes 
place  too  rapidly  to  permit  this  factor  to  be  given  much  weight. 


204  EPIDEMIOLOGY  OF  TUBERCULOSIS 

nity  of  the  majority  of  the  members  of  the  civilized  com- 
munity on  grounds  of  health.  In  fact,  it  is  impossible  to 
do  so  now  that  it  is  known  that  practically  all  civilized 
adults,  even  the  most  healthy,  have  undergone  a  tuberculous 
infection.  The  discovery  of  this  fact  is  of  hardly  less  im- 
portance in  phthisiology  than  the  discovery  of  the  tubercle 
bacillus.  Already  indicated  by  observations  at  autopsy,  it 
was  not  widely  accepted  until  the  brilliant  work  of  von  Pir- 
quet  and  others  with  the  tuberculin  reactions  proved  beyond 
cavil  that,  in  European  cities  at  least,  the  adult  population 
was  thoroughly  tuberculized.  The  facts  obtained  by  radiog- 
raphy on  the  healthy  subject,  which  show  that  there  is 
usually  evidence  of  a  localized  deep-seated  disease  of  the 
lung  that  differs  only  in  degree  from  that  which  goes  on  to 
produce  clinically  manifest  tuberculosis,  corroborate  fully 
the  results  of  the  tuberculin  tests  and  the  findings  of  the 
autopsy  table.  There  is  a  large  body  of  proof  from  three 
sources  in  support  of  the  proposition :  The  civilized  adult, 
almost  always,  if  not  invariably,  has  a  tuberculous  infec- 
tion. 

Unfortunately,  the  tendency  has  been  to  minimize  the 
results  of  these  investigations  or  to  attempt  to  explain  them 
away,  rather  than  to  face  the  issue  squarely  and  to  estab- 
lish the  real  facts.  The  importance  of  knowing,  for  example, 
whether  in  remote  places  in  our  country  where,  perhaps, 
there  have  been  no  known  cases  of  tuberculosis  for  many 
years  the  inhabitants  have  received  the  benefit  of  a  tuber- 
culous infection  or  not,  is  only  fully  realized  when  we  study 
races  and  peoples  who  have  not  become  well  tuberculized. 
But  such  study  in  itself  furnishes  an  answer  to  the  above 
question,  for  tuberculosis  among  the  unprotected,  sweeping 
away,  as  it  may,  all  the  members  of  a  family,  even  some- 
times of  a  tribe,  is  found  to  have  terrors  entirely  foreign 


SUMMARY  AND  CONCLUSIONS  205 

to  our  usual  experience.1  We  then  comprehend  that  oui 
race  must  have  become  tuberculized  and  consequently  im- 
munized, otherwise  it,  too,  would  have  perished. 

If  all  are  tuberculized  and  if,  in  contrast  to  what  occurs 
where  it  is  a  new  disease,  the  civilized  community  derives 
a  large  measure  of  protection  against  the  more  deadly 
forms  of  tuberculosis  by  reason  of  that  tuberculization,  the 
large  majority  of  the  population  not  only  escaping  manifest 
disease,  but  escaping  it  as  well  when  much,  as  when  appar- 
ently not  at  all  exposed,  it  logically  follows  that  the  tuber- 
culous infection  has  conferred  an  immunity  against  infec- 
tion from  without,  also,  of  course,  that  when  tuberculosis 
does  become  manifest  the  cause  is  an  extension  of  the  infec- 
tion already  present  in  the  body  of  the  individual  (if  the 
disease  is  of  the  usual  chronic  type  which  would  exclude 
immediately  antecedent  infection).  The  inference  is  sup- 
ported by  analogy  with  the  facts  of  other  infectious  dis- 
eases —  in  malaria  there  is  no  reinfection  with  organisms 
of  the  same  type,  in  syphilis  reinfection  does  not  occur 
until  the  disease  has  become  cured.  There  is  no  good  rea- 
son why  disease  caused  by  the  virulent  and  highly  resistant 
tubercle  bacillus  should  form  an  exception  to  the  law  that 
reinfections  do  not  take  place  so  long  as  the  infectious  agent 
is  present. 

There  has  been  a  marked  diminution  of  late  years  in  the 
mortality  from  tuberculosis,  practically  none  in  its  mor- 
bidity. But  the  mortality  from  tuberculosis  rises  and  falls, 
in  a  general  way,  with  the  general  mortality  and  is  influ- 
enced like  the  latter  by  causes  that  operate  to  improve  or  to 
deteriorate  the   conditions   of  health   of  the   community. 


^renfell  finds  that  in  the  remotest  parts  of  Labrador  the  tuberculosis 
of  the  whites  is  sometimes  of  an  acute  and  extraordinarily  fatal  type. 
(Personal  communication  to  Estes  Nichols.) 


206  EPIDEMIOLOGY  OF  TUBERCULOSIS 

Statistical  study  shows  that  such  changes  occur  almost  ex- 
clusively in  the  mortality  of  chronic  phthisis  and  not  at  all 
in  the  mortality  of  tuberculosis  when  it  occurs  as  an  acute 
disease  —  primary  tuberculosis  acts  like  an  infectious  dis- 
ease, chronic  phthisis  does  not.  The  infection  of  tuberculo- 
sis, in  other  words,  whether  it  declares  itself  at  once  as  a 
manifest  disease,  or  only  after  the  lapse  of  years,  or  not  at 
all  during  a  long  life,  takes  place  when  there  is  an  oppor- 
tunity for  the  tubercle  bacillus  to  enter  the  body,  quite 
independently  of  the  health  of  the  individual,  the  sanitary 
conditions  of  the  community  in  which  he  lives,  etc. 
Whether  infection,  once  received,  shall  become  manifest  dis- 
ease or  not  depends  first  of  all  upon  the  size  of  the  initial 
infection,  but  in  all  except  the  largest  infections  also  upon 
the  health  of  the  individual  which  is  largely  influenced,  in 
turn,  by  the  sanitary  conditions  which  surround  him.  To 
prevent  infection  we  must  stop  the  dissemination  of  the 
tubercle  bacillus ;  to  prevent  the  already  infected  individual 
from  developing  tuberculous  disease  we  must  regulate  the 
conditions  of  his  health.  We  have  effected  something  in 
the  latter  direction,  nothing  at  all  apparently  in  the  former. 

The  belief  that  consumption  is  not  infectious  was  based 
upon  an  enormous  experience,  but  very  naturally  seemed 
erroneous  when  the  infectious  agent  became  known.  The 
study  of  many  years  was  required  to  show  that  the  belief 
contained  an  element  of  truth,  that  consumption  is  not  in- 
fectious for  those  who  have  already  a  tuberculous  infection, 
even  though  it  be  occult. 

When  the  infectiousness  of  tubercle  was  not  known  no 
connection,  naturally,  was  seen  between  the  brain  fever  of 
the  infant,  the  scrofula  of  the  child  and  the  consumption  of 
the  adult.  The  error  of  our  fathers  lay  in  failing  to  appre- 
ciate the  fact  that  consumption,  though  indeed  not  infec- 


SUMMARY  AND  CONCLUSIONS  207 

tious  for  the  civilized  adult,  was  sowing  bountifully  on 
every  side  the  seeds  of  death  for  the  child  unprotected  by  a 
previous  infection  with  tuberculosis.  The  error  of  modern 
times  is  to  deny  the  protective  influence  of  tuberculous  in- 
fection against  renewed  infection  from  without.  Thus  is 
solved  the  riddle  of  the  centuries.  Our  fathers  saw  one 
side  of  the  shield,  we  have  concentrated  our  attention  too 
much  upon  the  other! 

The  immunity  in  tuberculosis  differs  from  that  derived 
from  vaccination  because  it  depends  upon  a  continuing  in- 
fection. It  is,  therefore,  in  a  sense,  stronger  than  vacci- 
nation because  constantly  renewed,  but  it  has  a  serious  ele- 
ment of  weakness  in  that  it  demands  a  constant  active 
resistance  which  may  be  overcome,  so  that  the  subject 
though  immunized  against  tuberculosis,  may  nevertheless 
die  of  it!  Now,  immunity  against  a  disease  is,  properly 
speaking,  an  immunity  against  the  infectious  micro-organ- 
ism. It  does  not  necessarily  remove  the  results  of  the  in- 
fectious inflammation.  Thus,  in  the  case  of  a  boil  the 
afflicted  individual  has  a  high  immunity  against  the  pyo- 
genic organism  that  caused  the  boil,  for  he  does  not  die  of 
septicemia,  though  the  bacteria  may  at  times  be  found  in 
the  blood,  yet  he  is  dependent  upon  the  knife  of  the  sur- 
geon to  evacuate  the  contents  of  the  abscess.  Similarly 
with  regard  to  the  gumma  of  syphilis,  though  the  subject 
be  immune  against  reinfection  and  though  he  does  not  per- 
mit his  disease  to  extend  more  widely,  his  immunity  never- 
theless can  not  do  away  with  the  gumma  without  help.  So 
in  tuberculosis,  caseous  foci  of  any  considerable  size  are 
not  destroyed  by  the  immune  powers  of  the  human  organ- 
ism; they  must  be  walled  in  by  connective  tissue,  or  must 
escape  by  ulceration,  constituting  a  constant  menace  so  long 
as  they  are  present  in  the  body. 


208  EPIDEMIOLOGY  OF  TUBERCULOSIS 

We  recognize  two  degrees  of  immunity  in  tuberculosis: 
First,  immunity  against  the  tubercle  bacillus.  The  tuber- 
culous subject  who  is  not  overwhelmed  by  a  too  massive 
original  infection  has  an  immunity  against  the  tubercle 
bacilli  which  circulate  in  his  blood  from  time  to  time  and 
also  against  those  which  may  enter  the  body  from  without 
Second,  immunity  against  tubercle  bacilli  and  the  accumu- 
lations of  their  poisonous  products,  such  immunity  not 
being  understood  as  power  to  eliminate  such  collections, 
but  simply  as  the  ability  to  restrain  existing  foci  from  ex- 
tending. It  might,  perhaps,  be  better  expressed  as  the 
ability  of  the  living  tissues  to  maintain  their  vitality  when 
bathed  in  juices  poisoned  by  the  tubercle  bacillus. 

Given,  therefore,  the  presence  of  a  good-sized  caseation 
(which  may  be  the  consequence  of  a  large  infection,  or  of 
some  later  lapse  in  the  immunity),  the  prognosis  becomes 
doubtful  in  direct  proportion,  other  things  being  equal,  to 
the  size  of  the  focus.  The  subject  may  die  of  an  extension 
of  his  disease,  but  in  pulmonary  tuberculosis  will  preserve 
until  near  the  close  of  life  the  first  degree  of  immunity,  that 
is,  he  will  develop  no  distant  foci  due  to  his  own  bacilli  and 
will  be  immune  to  the  incursions  of  tubercle  bacilli  from 
without. 

From  a  wide  survey  of  the  incidence  and  severity  of 
tuberculosis  in  many  countries  it  would  seem,  if  we  may 
trust  the  facts  obtainable,  that  the  degree  of  immunization 
is  the  highest  in  the  oldest  and  most  stable  communities 
and  that  the  immunization  of  the  savage  or  semi-civilized 
community  is  less  satisfactory  than  that  commonly  ob- 
tained in  our  civilization.  This  we  would  ascribe  to  the 
constant  interchange  in  our  civilization  of  articles  that  pasa 
through  many  unknown  hands  which  practically  insures  the 
ubiquitousness  of  the  dried  tubercle  bacillus,  which  is  an 


SUMMARY  AND  CONCLUSIONS  209 

advantage,  for  it  insures  that  the  inevitable  and  indeed  de- 
sirable tuberculization  shall  be  accomplished  in  most  cases 
by  means  of  a  somewhat  attenuated  bacillus  and  that  the 
infecting  dose  will  be  usually  small. 

Tuberculous  infection  does  not  appreciably  affect  the 
health  of  the  large  majority  of  the  population  who  remain 
throughout  life  immune  to  tuberculous  disease.  A  certain 
percentage,  however,  represent  failures  of  the  immunizing 
process,  but  in  many  if  not  the  greater  part  of  these  the 
failure  in  the  immunity  is  partial  and  comparatively  slight, 
so  slight  that  we  encourage  every  one  to  hope  for  recovery 
and  that,  so  nicely  balanced  are  the  forces  of  offense  and  of 
defense,  we  expect  the  scale  to  be  turned  in  the  right  direc- 
tion by  the  means  of  such  comparatively  trivial  remedies  as 
a  little  more  rest,  fresh  air  and  nourishing  food !  Not  thus 
does  one  cure  primary  tuberculosis;  the  sanatorium  treat- 
ment would  be  folly,  if  it  were  not  that  we  can  count  upon 
the  assistance  of  an  immunization  which  can  generally  be 
easily  induced  to  reassert  itself. 

Experience  shows  that  many  of  the  tuberculized  have  an 
iron  immunity  which  no  fatigue,  hardship  or  intercurrent 
disease  can  shake,  but  there  is  a  vast  number  of  persons,  in 
the  aggregate,  whose  fate  as  to  the  outbreak  of  manifest 
tuberculosis  will  depend  upon  the  state  of  their  health.  It 
should  be  one  of  the  achievements  of  the  future  to  deter- 
mine why  there  is  this  difference  in  the  amplitude  of  the 
margin  of  safety  of  the  two  groups.  We  may  conjecture 
that  it  consists  usually  in  a  larger  initial  infection  in  the 
less  resistant  class;  that  this  is  not  the  sole  cause  appears 
to  be  shown  by  the  rare  cases  in  which  miliary  tuberculosis 
attacks  an  individual  who  has  but  very  slight  and  old 
tuberculous  lesions. 


210  EPIDEMIOLOGY  OF  TUBERCULOSIS 

Modern  civilization  brings  with  it  inevitably  a  tubercu- 
lization.  There  appears  to  be  no  escape  from  this  without 
more  radical  changes  in  our  mode  of  life  than  can  be  rea- 
sonably anticipated,  so  long  as  the  cow  continues  to  play  a 
prominent  part  in  supplying  the  daily  food.  There  is,  how- 
ever, no  reason  for  alarm  in  the  fact  that  the  modern  world 
is  a  tuberculous  world.  The  present  situation  doubtless 
leaves  much  to  be  desired,  but  it  is  to  be  remembered  that 
it  has  greatly  improved  within  the  last  fifty  years  without 
our  conscious  interposition  —  what  can  we  not  make  of  it 
when  we  do  our  best!  We  have  simply  to  follow  the  indi- 
cations that  nature  grants  us  and  resolve  that  the  already 
large  percentage  of  the  immune  shall  be  increased  to  one 
hundred  per  cent!  Better  care  of  the  infant  and  the  in- 
auguration of  an  intelligent  instruction  of  the  mothers  is 
the  best  way  in  which  so  happy  a  state  can  be  approxi- 
mated. The  study  of  the  tuberculosis  of  the  Orient  leads 
to  the  suspicion  that  good  hygiene,  however  important  and 
highly  to  be  desired  it  may  be,  is  of  distinctly  minor  im- 
portance in  comparison  with  an  optimal  tuberculization. 

The  infants  who  die  with  miliary  tuberculosis  are  sacri- 
ficed uselessly  —  they  contribute  nothing  to  the  mainte- 
nance of  the  tuberculization  of  the  community.  On  the 
other  hand,  the  consumptive,  much  to  be  dreaded  as  he  is 
at  close  quarters  for  the  uninfected,  is  indispensable  in  the 
present  era  because  he  unwittingly  provides  for  that  immu- 
nization which  prevents  our  race  from  perishing  as  so 
many  other  races  have  perished  when  thrust  unprepared 
into  the  midst  of  infection.  Whether  a  correction  is  needed 
here  because  the  healthy  bacillus-carrier  could  perform  this 
function  unaided  is  a  doubtful  question,  the  answer  to 
which  can  only  be  obtained  by  much  investigation. 


SUMMARY  AND  CONCLUSIONS  211 

However  that  may  be,  should  we  not  look  forward  to  the 
time  when  nature's  methods  of  tuberculization,  so  terribly 
wasteful  of  human  life,  shall  be  replaced  by  a  thoroughly 
scientific  method  of  artificial  inoculation  in  which  no  life 
will  need  to  be  sacrificed  ? 


INDEX 


Africa  (see  Algeria,  Congo,  Dahomey,  Ivory  Coast,  Senegambia,  etc.), 
extension  of  tuberculosis,  by  itinerant  vendors,  118;  from 
employment  of  natives  as  miners,  166. 

German  East,  Hindoos  spread  contagion  in,  107. 
tuberculin  tests  in,  92,  107. 

German  Southwest,  danger  of  tuberculosis  in,  195. 
extermination  of  natives  in,  194. 

South,  consumptives  spread  tuberculosis,  121. 

tropical,  tuberculosis  in,  30. 
Africans,  tropical,  mortality  of,  166. 
Albrecht,  tuberculosis  of  bronchial  glands,  114. 
Algeria,  tuberculin  tests  in,  110. 
Almy,  tuberculosis  in  China,  38. 

Altstaedt,  complement  binding  reaction  in  young  children,  188. 
American  soldiers,  cutaneous  tuberculin  reaction  in,  96,  97. 
A  nam,  tuberculin  test  in,  104. 

Apache  Indian  prisoners,  mortality  from  tuberculosis  among,  157. 
Ashford,  tuberculosis  in  Porto  Rico,  54,  56. 

uncinariasis  in  Porto  Rico,  56. 
Aiistrian  soldiers,  cutaneous  tuberculin  reaction  in,  98. 

Babes,  incubation  of  leprosy,  64. 
Bacillus-carriers,  in  tuberculosis,  63,  110. 

in  pneumonia  and  meningitis,  190. 
Baldwin,   economic    conditions   cause   of   tuberculosis   in   negroes    of 

Washington,  154. 
Bandelier,  statistics  of  subcutaneous  tuberculin  reaction,  95. 
Barracks,  discontinuance  of,  lessens  pneumonia  at  Panama,  119. 

favor  spread  of  infections,  119. 
Barret,  tuberculosis  in  Smyrna,  41. 

Bergmann,  introduction  of  the  tuberculous  among  children,  179. 
Blin,  treatment  of  tuberculosis  at  Mayotte,  139. 

tuberculosis  in  Dahomey,  30. 
Bolivia,  tuberculosis  in,  133. 

Bourret  and  Bourrague,  cutaneous  tuberculin  tests  in  Senegambia,  105. 
Brazil,  tuberculosis  in,  45. 
Brewer,  mortality  from  tuberculosis  among  the  Indians,  161. 

in  Manila,  43. 
British  Guiana,  tuberculosis  in,  31. 
Bruns,  cutaneous  tuberculin  reaction  among  American  soldiers,  96. 

mortality  from  tuberculosis  in  Germany,  19. 
Buisson,  tuberculosis  in  the  Marquesas,  58. 
Burckhardt,  indications  of  tuberculosis  at  autopsy,  196. 

Cahnette,  cutaneous  tuberculin  tests,  103. 

impossibility  of  the  eradication  of  tuberculosis,  128. 
tuberculosis  in  New  Caledonia,  48;  at  Reunion,  42. 
Charleston,  S.  C,  tuberculosis  records  of,  142. 

213 


214  INDEX 

Children,  infection  of,  with  bovine  tubercle  bacilli,  180. 

introduction  of  the  tuberculous  among,  78,  179. 

prophylaxis  of  tuberculosis  in,  177. 

protection  of,  through  tuberculization  of  the  community,  181. 

relation  of  tuberculous  infection  to  age,  178. 

tuberculosis  in,  18,  22,  24,  74. 

tuberculous,  systematic  study  of,  184. 

young,  reaction  of,  to  complement-binding  tests  for  tuberculosis, 
188. 
Chile,  tuberculosis  in,  82. 
China,  tuberculosis  in,  35. 

Chota  Nagpur,  consumptives  cause  extension  of  tuberculosis  in,  120. 
Clark,  primary  tuberculosis  at  Panama,  82. 
Climate,  as  curative  agent  in  tuberculosis,  2. 

of  Samoa,  52. 

of  tropics  in  treatment  of  tuberculosis,  132. 
Cochin  China,  tuberculosis  in,  39. 
Colombia,  tuberculosis  in,  134. 

Colored  troops  of  the  U.  S.,  tuberculosis  statistics  of,  144. 
Complement-binding  reaction  in  tuberculosis,  187. 

results  in  young  children,  188. 
Congo,  Belgian,  tuberculin  tests  in,  106. 
tuberculosis  in,  89. 

French,  tuberculosis  in,  11. 
Consumption  as  a  non-infectious  disease,  8,  9. 

Consumptives,  spread  tuberculosis  at  Chota  nagpur,  120;   in   South 
Africa,  121. 

do  not  spread  tuberculosis  at  Davos,  Goerbersdorf,  etc.,  122. 
Cottle,  tuberculosis  in  Samoa,  50. 
Cummings,  economic  conditions  as  cause  of  tuberculosis,  154. 

Dahomey,  tuberculosis  in,  30. 
Depot  reactions,  96. 

combined  with  stich  reactions,  101. 
Deycke,  tuberculosis  in  Turkey,  83. 
Dold,  mortality  of  tuberculosis  in  Shanghai,  37. 
Dudgeon,  tuberculosis  in  China,  36. 
Dutroulau,  tuberculosis  in  the  tropics,  5. 

Economic   conditions,   as   cause  of   tuberculosis   in   Edinburgh,    155; 

Hamburg,  155;  among  the  negroes,  154. 
Edinburgh,  economic  conditions  cause  of  tuberculosis  in,  155. 
Epidemic  of  tuberculosis,  acute,  in  Berlin,  174. 

alleged  in  United  States,  175. 

chronic  in  Paris,  171. 
Epidemics,  of  chronic  tuberculosis,  explanation  of,  172. 
Epidemiology  of  tuberculosis,  comparative,  199. 
Eurasians,  liability  of,  to  tuberculosis,  38. 

Ferreira,  tuberculosis  in  Brazil,  45. 

Fishberg,  complement-binding  reaction  in  tuberculosis,  188. 

economic  conditions  as  cause  of  tuberculosis,  154. 

relation  of  tuberculous  infection  to  age  of  children,  179. 
Fraenkel,  A.,  tuberculosis  of  early  childhood,  74. 

in  prisons,  15. 
French  Guiana,  tuberculosis  in,  46. 

cutaneous  tuberculin  test  in,  106. 
Freund,  cutaneous  tuberculin  reaction  in  Austrian  soldiers,  98. 


INDEX  215 

Gaide,  tuberculosis  in  Tonkin,  39. 
Gallup,  on  tuberculosis,  etiology  of,  3. 

treatment  of,  3. 
Gamier,  tuberculosis  in  French  Congo,  11. 
Gebhardt,  economic  conditions  as  a  cause  of  tuberculosis  in  Hamburg, 

155. 
Geographical  location,  does  not  determine  type  of  tuberculosis,  137, 138. 
German  West  Carolinas,  tuberculosis  in,  59. 
Germany,  mortality  from  tuberculosis  in,  17,  19. 
Gorgas,  spread  of  pneumonia  in  barracks,  119. 
Gouzien,  tuberculosis  in  French  India,  31. 
Grieve,  tuberculosis  in  British  Guiana,  31. 
Guadeloupe,  cutaneous  tuberculin  tests  in,  104. 
Guam,  tuberculosis  in,  49. 

hospital  for  tuberculosis  in,  132. 

Hamburg,  economic  conditions  cause  of  tuberculosis,  155. 

Hamburger,  tuberculin  tests,  100. 

Harbitz,  tuberculosis  of  lymphatic  system,  73. 

Health,  does  not  prevent  tuberculous  infection,  191. 

Health  resorts,  in  the  tropics,  132,  136. 

Heim,  tuberculosis  in  German  Samoa,  32. 

Heinemann,  cutaneous  tuberculin  tests  in  Sumatra,  109. 

primary  tuberculosis  in  Sumatra,  80. 
Heiser,  tuberculosis  at  Manila,  42. 
Henaff,  tuberculosis  in  Cochin  China,  39. 
Hirsch,  eiology  of  tuberculosis,  8. 

Hrdlicka,  cutaneous  tuberculin  tests  in  Indian  children,  192. 
Hunter,  intemperance  among  Indians  as  cause  of  tuberculosis,  191. 
Hutchinson,  primary  tuberculosis  in  Indians  of  Northwest,  75. 
Hygienic  care,  absence  of,  at  Lippspringe,  does  not  increase  tuber- 
culosis, 124. 

India,  French,  tuberculosis  in,  Gouzien,  31. 

British,  tuberculosis  in,  40. 

British  army  in,  tuberculosis  of,  41. 
Indian  children,  cutaneous  tuberculin  tests  in,  193. 
Indian  habitations  in  causation  of  tuberculosis,  160,  162. 
Indian  tribes,  mortality  from  tuberculosis  in,  161. 

of  Southwest,  tuberculosis  mortality  not  explained  by  change  of 
life,  162. 
Indian  troops  of  the  United  States,  156;  tuberculosis  statistics  of,  146. 
Indians,  tuberculosis  from  intemperance  in,  191. 

of  Northwest,  tuberculosis  in,  75. 
Infection,  modes  of,  in  tuberculosis,  62. 
Ivory  Coast,  cutaneous  tuberculin  tests  on,  106. 

Jamaica,  uncinariasis  in,  32. 

Java,  tuberculosis  in,  78. 

Jerusalem,  cutaneous  tuberculin  reaction  in,  92. 

tuberculosis  in,  65. 
Johnston,  tuberculosis  in  British  army  in  India,  41. 
Jourdanet,  tuberculosis  in  Yucatan,  7. 

Kaiser  Wilhelmsland,  cutaneous  tuberculin  tests  in,  108. 
Kalmucks,  cutaneous  tuberculin  tests  among,  111. 
Kamerun,  cutaneous  tuberculin  tests  in,  91,  107. 


216  INDEX 

Kennedy,    extension    of    tuberculosis    from    consumptives    at    Chota 

Nagpur,  120. 
Kermorgant,  tuberculosis  in  New  Caledonia,  47. 
Kersten,  cutaneous  tuberculin  tests  in  Kaiser  Wilhelmsland,  108. 
Kober,  housing  conditions  of  negroes  of  Washington,  150. 
Kopp,  cutaneous  tuberculin  tests  in  New  Pomerania,  108. 
Kuhn,  danger  from  consumptives  in  South  Africa,  122. 
Kiilz,  danger  of  tuberculosis  in  German  Southwest  Africa,  195. 

Laboratory  methods  for  study  of  natural  tuberculous  infection,  189. 
Laennec,  contagiousness  of  tuberculosis,  1. 
La  Paz,  climatic  treatment  of  tuberculosis  at,  133. 
Law  of  Romer,  202. 
LeMoine,  tuberculosis  in  Oceania,  29. 
Leprosy,  incubation  of,  analogous  with  tuberculosis,  64. 
Lidin,  tuberculosis  in  Martinique,  41. 
Lippspringe,  tuberculosis  mortality  at,  124. 
Lohlein,  healed  tuberculosis  at  autopsy  in  Kamerun,  78. 
Lungs,  congestion  of,  a  cause  of  extension  of  tuberculosis,  198. 
Lymph  glands,  in  primary  tuberculosis,  72,  81. 
tuberculosis  of,  73,  79. 

Mackenzie  Valley,  Indian  mortality  from  tuberculosis  in,  160. 

Macpherson,  tuberculosis  in  British  army  in  India,  40. 

Macvicar,    extension    of    tuberculosis    from    consumptives    in    South 

Africa,  121. 
Manila,  chronicity  of  tuberculosis  in,  43. 

mortality  from  tuberculosis  in,  43. 

prophylaxis  and  treatment  of  tuberculosis  in,  131. 
Manteufel,  cutaneous  tuberculin  tests  in  German  East  Africa,  92,  107. 
Maoris,  tuberculosis  among,  32. 

Marfan,  epidemic  of  chronic  pulmonary  tuberculosis  in  Paris,  171. 
Marquesas,  tuberculosis  in,  58. 

Martinique,  tuberculosis  in,  41 ;  cutaneous  tuberculin  test  in,  104. 
Mayer,  tuberculosis  in  German  West  Carolinas,  59. 

in  Tropical  Africa,  30. 
Mayotte,  treatment  of  tuberculosis  by  natives,  139. 
McCarthy,  tuberculosis  in  Panama,  59,  178. 
McDill,  tuberculosis  in  China,  37. 
Mesnard,  tuberculosis  in  New  Caledonia,  49. 

Metchnikoff,  cutaneous  tuberculin  tests  among  the  Kalmucks,  110. 
Mexican  plateau,  tuberculosis  in,  136. 
Mirauer,  cutaneous  tuberculin  tests  with  dilutions,  93. 
Morales,  climatic  treatment  of  tuberculosis  at  La  Paz,  133. 
Mortality  from  phthisis,  17. 

tuberculosis  among  the  non-immunized,  59,  61,  75,  109,  162,  165, 
167. 

tuberculosis  in  Shanghai,  37. 
Mouchet,  cutaneous  tuberculin  tests,  Belgian  Congo,  106. 

tuberculosis  in  Belgian  Congo,  81. 
Much,  cutaneous  tuberculin  reaction  at  Jerusalem,  92. 

tuberculosis  in  Jerusalem,  65. 
Musgrave,  chronicity  of  tuberculosis  in  Manila,  43. 
Muthu,  tuberculosis  in  India,  40. 

Naegeli,  indication  of  tuberculosis  at  autopsy,  196. 
Negro  population,  large  cities  of  the  United  States,  tuberculosis  mor- 
tality of,  150;  of  Washington,  149. 
of  United  States,  tuberculous  infection  of,  in  slavery,  142. 


INDEX  217 

New  Caledonia,  tuberculosis  in,  46. 

New  Pomerania,  cutaneous  tuberculin  tests  in,  108. 

Nothmann,  depot  tuberculin  reactions,  96. 

Oceania,  tuberculosis  in,  29. 

Odell,  tuberculosis  in  Guam,  49. 

Opie,  discovery  of  tuberculosis  by  radiographic  methods,  188. 

Panama,  discontinuance  of  barracks  lessens  pneumonia,  119. 

tuberculosis  in,  59,  82. 
Parrot,  cutaneous  tuberculin  tests  in  Algeria,  110. 
Peiper,  cutaneous  tuberculin  tests  in  German  East  Africa,  107. 
Peruvian  army,  tuberculosis  in,  134. 
Philippines,  diseases  predisposing  to  tuberculosis  in,  42. 

tuberculosis  in,  42. 
Phthisis,  mortality  from,  17. 

v.   Pirquet,   cutaneous    tuberculin   reaction    negative    in    tuberculous 
children,  96. 

reaction,  see  cutaneous  tuberculin  reaction. 
Pneumonia,  cause  of  high  mortality  from,  in  the  South,  167. 

statistics  of,  Africa,  167;  Panama,  119. 
Pollak,  introduction  of  tuberculous  patient  among  children,  178. 
Porto  Rico,  tuberculosis  in,  54. 

uncinariasis  in,  56. 
Power,  mortality  from  tuberculosis  of  natives  of  Tasmania,  165. 
Predisposition  in  tuberculosis,  2,  9,  17. 

Queensland,  health  resort  for  consumptives,  136. 

Ramsey,  reaction  of  bone  and  joint  tuberculosis  to  tuberculin,  93. 
Ranke,  influence  of  age  upon  tuberculosis,  28. 

mortality  from  tuberculosis  in  Germany,  17. 
Reinfection,  in  tuberculosis  endogenous,  70,  205. 
Reports,  annual,  Commissioner  of  Indian  Affairs,  162. 

Inspector  General,  United  States  Army,  156,  158. 

Surgeon  General  United  States  Army,  145,  157. 

Surgeon  General  United  States  Navy,  132,  155. 
Reunion,  cutaneous  tuberculin  test  in,  104. 

tuberculosis  in,  42. 
Ritter,  cutaneous  tuberculin  tests  with  dilutions,  93. 

negative  subcutaneous  tuberculin  reactions  in  the  tuberculous,  95. 
Rochard,  etiology  of  tuberculosis  in  Tahite,  5. 

treatment  of  Europeans  in  tropics,  11. 
Rocky  Mountain  Plateau,  tuberculosis  in,  136. 
Rbmer,  law  of,  202. 

Salecker,  tuberculin  skin  tests  in  the  Ladrones,  104. 
Samanez,  tuberculosis  in  the  Peruvian  army,  134. 
Samoa,  American,  tuberculosis  in,  50. 

climate  of,  52,  53. 

etiology  of  tuberculosis  in,  4. 

German,  tuberculosis  in,  32. 
Sanitation,  effect  of,  on  extension  of  tuberculosis  in  South  Africa,  122. 

role  of  in  prophylaxis  of  tuberculosis,  129. 
Shanghai,  mortality  of  tuberculosis  in,  37. 
Sioux  prisoners  of  war,  tuberculosis  among,  159. 
Smyrna,  tuberculosis  in,  41. 
Sorel,  cutaneous  tuberculin  tests  on  the  Ivory  Coast,  106. 


218  INDEX 

Stacey,  cutaneous  tuberculin  reaction  in  American  soldiers,  97. 
Stefansson,  Indian  habitations  and  tuberculous  infection,  160. 
Stevenson,  R.  L.,  climate  of  Samoa,  53. 

cured  of  tuberculosis  in  tropics,  132. 

mortality  of  tuberculosis  in  the  Marquesas,  58. 
"  Stick  "  reaction,  102. 
Sumatra,  primary  tuberculosis  in,  80. 

cutaneous  tuberculin  tests  in,  109. 
Surgeon  General  United  States  Army,  Annual  Reports  of,  145,  147. 

Tahite,  etiology  of  tuberculosis  in,  5. 

Tasmania,  mortality  of  natives  from  tuberculosis,  165. 

Tierra  del  Fuego,  tuberculosis  in,  61. 

Tonkin,  tuberculosis  in,  39. 

cutaneous  tuberculous  test  in,  104. 
Treutlin,  climatic  treatment  of  tuberculosis  at  La  Paz,  133. 
Tropical  countries,  classified  as  to  tuberculosis,  34. 
Tropics,  climate  of,  in  treatment  of  tuberculosis,  133,  134,  136. 
cure  of  tuberculosis  in,  131,  132. 
tuberculosis  in,  Dutroulau's  views,  5. 
treatment  of  tuberculosis  in,  138. 
Tubercle    bacilli,   bovine,   infection   with,   how    related   to   that   with 

human  type  in  youngest  children,  180. 
Tuberculin,  cutaneous  reaction  compared  with  prevalence  of  tuber- 
culosis of  bronchial  glands,  114. 
parallelism  of,  with  clinical  course  of  tuberculosis,  113. 
types  of,  99. 

cutaneous  test,  by  countries,  Algeria,  110;  Anam,  104;  Belgian 
Congo,  106;  French  Guinea,  106;  German  East  Africa, 
92,  107;  Ivory  Coast,  106;  Jerusalem,  92;  Kaiser  Wil- 
helmsland,  108;  Kalmucks,  111;  Kamerun,  91,  107;  La- 
drones,   104;    Lille,   104;    Martinique,   104;    New   Pome- 
rania,   108;   Reunion,   104;   Senegambia,   105;    Sumatra, 
109. 
with  dilutions,  93. 
epidemiological  use  of,  117. 
inadequacy  of,  114. 
in  Indian  children,  192. 
negative  reactions  to,  95. 

in  bone  and  joint  tuberculosis,  93. 
in  tuberculous  children,  96. 
in  soldiers,  American,  96,  97;  Austrian,  98. 
standardization  of,  186. 
tests,  directions  for  use  of,  99. 

subcutaneous,  control  injections  in,  102. 
depot  reaction  in,  96,  101. 
dosage  in,  100. 
negative  in  tuberculosis,  95. 
statistics  of,  95. 
stich  reaction  in,  102. 
Tiiberculization,   of   the   community,   advantages    and   disadvantages 
of,  181. 
importance  of  its  study,  184,  187,  188. 
inevitability  of,  210. 
protection  of  the  children  by,  181. 
Tuberculosis,  acute  miliary,  a  pathological  accident,  21. 
not  affected  by  general  sanitation,  24. 


INDEX  219 

acute  pulmonary,  signs  and  symptoms  of,  90. 

artificial  infection  with,  184. 

bacillus-carriers  in,  63,  110. 

of  bones  and  joints,  tuberculin  reaction  in,  93. 

of  bronchial  glands,  compared  with  cutaneous  reaction,  114. 

of  childhood,  74. 

chronic  forms  of,  absence  of  at  early  age,  how  explained,  170. 

chronic  pulmonary,  duration  of  infection  in,  170. 
mortality  of,  not  that  of  infectious  disease,  24. 

chronicity  of,  in  Manila,  43. 

climate  as  a  curative  agent  in,  2. 

climatic  treatment  of,  133,  134,  136. 

compared  with  typhoid  fever,  24. 

complement-binding  reaction  in,  187. 
results  of,  in  young  children,  188. 

contagiousness  of,  1. 

by  countries;  Africa,  South,  121;  tropical,  30;  American  Samoa, 
50;  Belgian  Congo,  81;  Bolivia,  133;  Brazil,  45;  British 
Guiana,  31;  Ceylon,  59;  Chile,  82;  Cochin  China,  39; 
China,  35;  Colombia,  134;  Dahomey,  30;  French  Guiana, 
(Cayenne),  46;  French  Congo,  11;  French  India,  39; 
German  Samoa,  32;  German  Southwest  Africa,  194; 
German  West  Carolinas,  59;  Guam,  49;  India,  40;  Java, 
78;  Maoris,  32;  Marquesas,  58;  Martinique,  41;  Mexican 
Plateau,  136;  New  Caledonia,  46;  Oceania,  29;  Panama, 
59,  82;  Philippines,  42;  Porto  Rico,  54;  Reunion,  42; 
Rocky  Mountain  Plateau,  136;  Tasmania,  165;  Tierra 
del  Fuega,  61 ;  Tonkin,  39 ;  Turkey,  83 ;  Yucatan,  7. 

cure  of,  in  tropics,  131,  132. 

detection  of,  by  X-ray  at  autopsy,  188. 

economic  conditions  cause  of,  154. 

epidemic  of,  acute,  in  Berlin,  174. 
how  determined  to  exist,  172. 
chronic  pulmonary,  Paris,  171;  United  States,  175. 

etiology  of,  3,  4,  5,  8. 

extension  of,  affected  by  sanitation  in  South  Africa,  122. 

caused  by  consumptives  in  Chota  Nagpur,  120;  South  Africa, 

121. 
by  itinerant  vendors  in  Africa,  118. 

not  caused  by   consumptives   at   Davos,   122;    Goerbersdorf, 
Falkenstein,  123;  Lippspringe,  124. 

generalized,  18. 

immunity  in,  69,  88,  207. 

immunizing  infections  in,  65,  113. 

impossible  to  eradicate,  128. 

incubation  of,  analogy  with  leprosy,  64. 

in  Indian  habitations,  160,  162. 

indications  of,  at  autopsy,  77,  196. 
by  X-ray,  188. 

infection  of  children  with,  how  related  to  age,  178,  179. 
systematic  study  of,  184. 
with  human  and  with  bovine  baccilli,  how  related,  180. 
natural,  study  of  in  laboratory,  189. 
not  prevented  by  good  health,  191. 

influence  of  age  upon,  27,  28. 

intemperance  as  cause  among  Indians,  191. 

latency  of,  15,  25. 


220  INDEX 

lesions  of  post  mortem,  76,  83. 

of  lymph  glands,  73,  79,  86. 

meteorological  conditions  as  cause  of,  3,  5. 

modes  of  infection  in,  62. 

mortality  from,  of  Apache  prisoners,  157. 

in  Germany,  17,  19. 

in  Indians  of  Southwest  not  explained  by  change  of  life,  162 

in  Indian  tribes,  161. 

at  Lippspringe,  124. 

in  Manila,  43. 

of  natives  of  Tasmania,  165;  Tierra  del  Fuego,  61. 

of  negroes,  large  cities  of  United  States,  150. 

among  the  non-immunized,  59,  61,  75,  109,  160,  162,  165. 

at  Schlangen,  127. 

in  Shanghai,  37. 

in  Smyrna,  41. 

of  tropical  Africans  at  mines,  166. 

in  tuberculized  community,  varies  with  general  mortality,  24 

at  Washington,  D.  C,  149,  152. 
in  Peruvian  army,  134. 
predisposition  in,  2,  9, 14. 

to,  from  uncinariasis  in  Philippines,  42. 
primary  in  African,  78,  81,  88. 

of  childhood,  74. 

an  infectious  disease,  24. 

in  Labrador,  205. 

lymph  glands  in,  73,  81. 

in  Panama,  59,  78,  82. 

in  Sumatra,  80. 
in  prisons,  15. 

prophylaxis  and  treatment  of,  in  Manila,  131. 
records  of  Charleston,  S.  C,  142. 
reinfection  of,  endogenous,  70,  205. 
in  slaves  of  United  States,  142. 
statistics  of,  in  United  States  troops,  colored,  144;  Indian,  146; 

white,  145;  in  Philippines  and  Hawaii,  146,  148. 
treatment  of,  at  Manila,  131;  at  Guam,  132;  at  Mayotte,  139. 

by  non-expert,  evils  of,  140. 

in  tropics,  131,  132,  138. 
in  tropics,  classification  of,  34. 

Dutroulau's  views  on,  5. 

etiology  of,  5,  7,  11. 
type  of,  changed  by  tuberculization,  41,  58,  66,  79,  112. 

not  determined  by  geographical  location,  137,  138. 
and  uncinariasis  in  Jamaica,  32. 
in  West  Indian  regiment,  32. 
Tuberculous  lesions,  causes  of  progression  of,  198. 

as  vaccination  against  tuberculosis,  70. 
Tuberculous  patients,  instruction  of,  139. 
introduction  of,  among  children,  178. 
isolation  of,  among  non-immunized,  120. 
prejudicial  habits  of,  139. 
Turkey,  tuberculosis  in,  83. 
Turner,  etiology  of  tuberculosis  in  Samoa,  4. 
Typhoid  fever,  compared  with  tuberculosis,  24. 

Uncinariasis  in  Jamaica  as  cause  of  tuberculosis,  32. 
in  Porto  Rico,  56. 


INDEX  221 

United  States  Army  Hospital,  No.  21,  tuberculin  tests  at,  97. 

Vaccination  against  tuberculosis  through  tuberculous  lesions,  70. 

Vargas,  tuberculosis  in  Colombia,  134. 

Vaughn  and  Palmer,  high  mortality  of  rare  communicable  diseases, 

167. 
Virchow,  epidemic  of  tuberculosis,  174. 

Wagon,  cutaneous  tuberculin  tests  in  French  Guinea,  106. 

Walker,  mortality  from  tuberculosis  in  Indians,  161. 

Washington,  D.  C.,  housing  conditions  of  negro  population  in,  150. 

tuberculosis  mortality  of,  149. 
Werner,  tuberculosis  situation  at  Lippspringe,  124. 
Westenhoeffer,  tuberculosis  in  Chile,  82. 
West  Indian  regiment,  tuberculosis  in,  32. 
White  troops  of  United  States,  tuberculosis  statistics  of,  145. 
Wilkinson,  tuberculosis  in  India,  40. 

Williams,  S.  Wells,  tuberculosis  in  China,  36  (footnote) . 
Williamson,  economic  conditions  cause  of  tuberculosis  in  Edinburgh, 
155. 

X-ray,  in  detection  of  tuberculosis  at  autopsy,  188. 
determination  of  tuberculosis  by,  103. 

Yucatan,  tuberculosis  in,  7. 

Zieman,  cutaneous  tuberculin  tests  in  Kamerun,  91,  107. 


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